Privacy Policy

Effective date: 2026-11-02 · Previous version: 2026-10-20

Who we are

This privacy policy applies to the mobile applications published by MintWave Studio on Google Play and, once released there, the Apple App Store, together with any related services we operate (each an "Application"). MintWave Studio is referred to as the "Service Provider", "we" or "us". Where a section applies only to some Applications, it says so.

Our published Applications are Hatch Day, Cable Calc, MultiTimer, Days Until, Daily Budget, Rhythm Trainer, Shadow Match, Trivia Showtime (formerly Smart Quiz), ZeroMargin, Steady Hand and Sire & Dam. This policy also covers Applications we are preparing (Endly, Relisto, Sweet Ledger, Nebari, Stickwise, Wirepass and InvoiceLens); their sections below apply once they are released.

Our Applications do not require an account. We do not ask for your name, email address or phone number inside the Applications, and we do not operate our own servers that store your app content. The only server we run is the listing server for Relisto (not yet released), which processes item photos to write listing text and does not store them (see Relisto).

Information stored on your device

Most of what you create in our Applications stays on your device. Examples are your practice history, scores, routines, timers, budgets, lists, notes and settings, and any photos you add from your gallery. The Service Provider does not receive this information. You can delete it at any time through the delete or clear options in the Application, or by uninstalling the Application. If you have Android or iOS backup enabled, your device's operating system may include this data in your personal Google or Apple backup, which is governed by their privacy policies.

Some Applications let you share content (for example, a score report or a challenge code) through your device's share menu. Content is shared only when you choose to share it, and only with the apps and people you select.

Camera and text recognition (Days Until only)

If you choose to scan a date with your camera, the image is processed on your device using Google ML Kit text recognition to read the text. Camera images are not stored by the Application or sent to the Service Provider. Camera access is requested only when you use this feature, and you can revoke it in your device settings.

Notifications

Applications that offer reminders or timers schedule notifications locally on your device. No notification content is sent to the Service Provider.

Information collected automatically

Some Applications use the following third-party services. These services may collect information automatically when you use the Application.

Advertising (Google AdMob)

Free versions of some Applications show ads on Android, served by Google AdMob. AdMob may collect your device's Android Advertising ID, IP address, approximate location derived from the IP address, device and app information, and ad interaction data. It uses this information to deliver, measure and limit the frequency of ads, and, where you allow it, to personalize ads.

• Consent: In the European Economic Area, the United Kingdom, Switzerland and where otherwise required, the Application asks for your consent through Google's consent form before ads are requested. Ads are only requested once your choice allows it.
• Changing your choice: Where this applies, you can reopen the consent form at any time from the Application's menu under Privacy options.
• Advertising ID: You can reset or delete your advertising ID, or opt out of personalized ads, in your device settings (Android: Settings > Privacy > Ads).
• No ads on iPhone and iPad: the iOS versions of our Applications do not show ads, do not request ads, do not ask for tracking permission and do not use the Apple advertising identifier (IDFA).
• Pro users of Applications that offer a Pro upgrade do not see ads. Free users see only occasional full-screen ads at natural breaks (for example after finishing a run or a show), never banner ads, and the Application does not request ads for them.
• Endly never shows ads and does not use an advertising identifier.

Analytics (Google Firebase Analytics)

Endly does not use Firebase Analytics or Firebase Crashlytics. Some other Applications use Firebase Analytics to understand how features are used, so we can fix problems and improve the Application. It records usage events such as completing an activity, opening the upgrade screen, starting or completing a purchase, and being shown a rating request. It also collects device and app information (device model, operating system version, app version, language, country) and an app-instance identifier.

• Until you have made a consent choice, or if you decline, Firebase Analytics runs in a restricted mode without storing identifiers (Google Consent Mode).
• On iPhone and iPad there is no consent form, because the iOS versions show no ads. Firebase Analytics therefore always runs in this restricted mode there, without storing analytics identifiers.
• Analytics data is never used by us for ad personalization; the related advertising consent signals are always set to "denied".
• We do not log your app content (such as your scores, notes or budgets) as analytics events beyond the summary values described above.

Crash reporting (Google Firebase Crashlytics)

Some Applications use Firebase Crashlytics to receive reports when the Application crashes. A crash report contains technical details: the error and where it happened in the code, device model, operating system version, app version, the state of the app at the time (for example free space and orientation), and a randomly generated installation identifier. Crash reports do not include your app content.

Purchases (Google Play Billing, Apple App Store, RevenueCat)

Some Applications offer an optional paid "Pro" upgrade, either as an auto-renewing subscription or a one-time purchase. Payments are processed entirely by Google Play or the Apple App Store. We never receive or store your payment card or bank details.

• The Application receives your purchase history from Google Play or Apple (which product you bought, the purchase state and a purchase token). It uses this to unlock Pro, restore purchases and detect when a subscription ends. Your Pro status is also saved on your device so it works offline.
• Some Applications use RevenueCat to verify purchases and manage subscription status. RevenueCat receives the purchase information above together with an anonymous app user identifier generated by the Application.
• You can cancel or manage subscriptions at any time in Google Play (Payments & subscriptions) or in your Apple ID settings. Uninstalling the Application does not cancel a subscription.

Ratings (Google Play In-App Review)

Some Applications may occasionally ask you to rate them using Google Play's or Apple's in-app review prompt. Any rating or review you submit goes directly to the store under that store's terms. The Service Provider does not receive it through the Application.

App-by-app details

This section describes what each Application stores and whether anything leaves your device. Everything not mentioned here follows the general sections above. Unless stated otherwise, the Applications may use Firebase Analytics and Crashlytics, purchases and in-app review as described above. On Android, the free versions of Hatch Day, Cable Calc, Rhythm Trainer, Shadow Match, Trivia Showtime, ZeroMargin, Steady Hand and Sire & Dam show ads (see Advertising). The iOS versions show no ads. MultiTimer, Daily Budget and Days Until do not show ads and do not use an advertising identifier for ads.

Rhythm Trainer (rhythm and timing practice)

• On your device: your runs (tap timings, hand used, accuracy, unstable rate, timing offset and grades), run length, records, practice streak and minutes, routines, Daily Chart progress, your timing offset and note speed settings.
• Daily Chart: the day's chart is generated inside the Application from the date. Nothing is downloaded and there is no online leaderboard.
• Timing Coach: your saved runs are analysed on your device to find timing habits (for example rushing after rests or drifting late). The analysis and its results are not sent anywhere.
• No microphone: Rhythm Trainer scores your taps on the screen. It does not use the microphone.
• Analytics: usage events such as starting the Daily Chart or a routine, starting a Timing Coach drill, or applying a suggested timing offset (with the offset value) may be recorded as described under Analytics. Your tap timings are not sent.
• Challenge codes: when you share a run or a Daily Chart result, the code contains the pattern, tempo and your tap timings so a friend can play against it. It is shared only when you choose to share it.

Trivia Showtime (trivia game show, formerly Smart Quiz)

• Questions are built in: the question bank (based on the Open Trivia Database) is part of the Application. Trivia Showtime does not download questions and makes no request to opentdb.com.
• Host voices: the hosts speak using your device's own text-to-speech voices. Trivia Showtime does not use an online voice or AI service, and does not use the microphone.
• On your device: your chosen host, outfit and voice, sound and timer settings, shows played, wins, best score, answer statistics, daily streak and the list of questions you have already seen (so they are not repeated).
• Analytics: to keep question difficulty fair, the Application may record which question was answered (its number), its level, the round and whether the answer was right, plus a summary when a show ends (score, win, host). These events contain no free text and are described under Analytics.
• Reporting a question: if you report a wrong or outdated question, your email app opens with a pre-filled message to [email protected]. Nothing is sent until you press send; we then receive your email address and message and use them only to answer and fix the question.
• Sharing: your score is shared only when you choose to share it.
• Older Smart Quiz versions (before Trivia Showtime) downloaded questions from opentdb.com when online. That request contained only the number, category and difficulty of the questions and your IP address; no answers, scores or identifiers. It also scheduled a local evening streak reminder.

Steady Hand (hold-still challenge)

• Motion sensor: the accelerometer is read only while a test is running, to calculate your steadiness score. Sensor readings are processed on your device and are not stored or sent; only the resulting score is kept.
• On your device: scores, ranks, the grip you chose, daily challenge streak, achievements and party mode player names you type in.
• Steady Hand is a game, not a medical device. It does not collect or infer health information.

Shadow Match (3D puzzle)

• On your device: level progress, stars, Daily Shadow streak, settings and your hint balance (including hints bought in packs).

ZeroMargin (stopwatch game)

• On your device: your results, best margins, streaks, rank, achievements and duel results. There is no online leaderboard; your daily target result is shared only when you choose to share it.

Days Until (expiry date tracker)

• On your device: the items you track (names, dates, categories, storage locations, optional prices and notes), whether you used or tossed them, and your reminder settings. Items can include document details you type in, such as a passport or licence expiry date.
• Camera: see Camera and text recognition above. Images are processed on your device and not stored or sent.
• Reminders are scheduled locally. Backup and CSV files are created on your device and go only where you choose.

MultiTimer (multiple timers)

• On your device: timers, cards, presets, history and focus statistics.
• Alarms: the Application uses exact alarms, a foreground service and (when you allow it) full-screen alarms so timers ring on time. All of this runs locally.
• Custom alarm sound: if you pick your own sound, the Application keeps permission to read only that file. It is not copied or uploaded.
• Backup files are created on your device and go only where you choose.

Daily Budget (budget planner)

• On your device: budgets, income, bills, expenses, categories, limits, savings goals and notes. Daily Budget never connects to your bank and has no ads.
• Not in cloud backup: your financial data is excluded from Google's automatic cloud backup. It can be moved during a direct phone-to-phone transfer, and you can make your own backup file in the Application. Backup and CSV files go only where you choose; treat them as private.
• App lock: the PIN is stored on your device. Fingerprint or face unlock is handled by your phone's operating system; the Application never receives your biometric data.
• Analytics: amounts, category names and notes are never sent as analytics events.

Endly (endometriosis and symptom tracker), not yet released

• What you enter: pain levels and where it hurts, symptoms, bleeding, sleep, stress, possible triggers (such as food, exercise or sex), how pain affected your day, medications and doses, health events (such as appointments or surgery) and notes. This is health information.
• Where it is kept: only on your device. The Service Provider never receives it, and no third party receives it through the Application.
• No ads, no analytics, no crash reporting: Endly contains no advertising and does not use Firebase Analytics or Crashlytics. The only network connections it makes are for purchases (Google Play or the App Store, and RevenueCat, which receive only the purchase information described under Purchases, never your health entries).
• Backups: on Android, Endly's data is excluded from device and cloud backup, so it stays on the phone. On iPhone, it may be included in your own iCloud or computer backup, which Apple encrypts; you can turn iCloud Backup off for Endly in your iPhone settings.
• PIN lock: you can set a PIN that is required to open the Application. The PIN is stored on your device only.
• Encrypted backup (optional): you can save an encrypted copy of your Endly data to a location you choose (for example phone storage, Google Drive or iCloud Drive), once or automatically on a schedule you set. The copy is encrypted on your device (AES-256) with a password only you know; the Service Provider never receives the copy or the password. For automatic backups, a key derived from your password is kept in your device's secure storage (Keychain or Android Keystore), never the password itself. Where the copy is stored, and whether it syncs to a cloud service, is controlled by you and the storage provider you pick. You can turn automatic backup off at any time.
• Reports and exports: the doctor report, the impact report, the emergency card and CSV exports are files created on your device and saved only where you choose.
• Medical records (optional): photos or PDFs of documents you add (for example scan reports or letters) are copied into Endly's own storage on your device. They are included in your encrypted backup if you make one, and are deleted with "Delete all data".
• Home-screen widget (optional): shows only whether you logged today's pain and the number. On iPhone this number is shared with the widget through an app group on your device.
• Reminders (daily check-in and medication reminders) are scheduled locally on your device. Medication reminders show the medication name only after the phone is unlocked on Android; on iPhone, notification previews follow your iPhone settings.
• Endly is a tracking tool, not a medical device, and does not give a diagnosis.

Relisto (resale listing assistant), not yet released

• Camera and photos: used when you take or choose photos of items you want to sell. Photos are reduced in size on your device first.
• Writing a listing with AI: when you ask Relisto to write a listing, the Application sends, over an encrypted connection, up to two photos of the item, any details you typed (brand, size, notes), the language, currency and marketplace you chose, and the anonymous purchase identifier generated by the Application, to our listing server (hosted on Cloudflare Workers). The server passes the photos and details to Anthropic's Claude API, which writes the title, description and suggested price, and returns the result to your device.
• What is not stored: our server does not store your photos, details or the generated text. Anthropic processes them to produce the reply under its commercial terms, which do not allow it to use them to train its models, and keeps them only for a limited time under its own policies.
• What the server keeps: a count of AI listings per anonymous identifier for the current month (deleted after 40 days) to apply the free allowance and fair-use limit; a count of requests per IP address per day (deleted after 2 days) to prevent abuse; your Pro status, checked with RevenueCat and cached for up to 1 hour; and technical logs without photos or text (whether you have Pro, the language, and the amount of text processed).
• Please don't photograph people, documents or anything else with personal information, and don't type personal information into the notes. Photos are only meant to show the item.
• On your device: items, photos, prices, listing text and sales records. Listings reach a marketplace only when you copy or share them there yourself; that marketplace's privacy policy then applies.

Sweet Ledger (bakery pricing and orders), not yet released

• On your device: ingredients, recipes, costs, prices, and orders, including the customer details you enter (name, phone number, delivery address and notes).
• Your customers' data: if you record information about your customers, you are responsible for it under the privacy laws that apply to your business. The Service Provider never receives it.
• WhatsApp: the WhatsApp button opens WhatsApp with a pre-filled quote or message to the number you entered. Nothing is sent until you press send in WhatsApp, and WhatsApp's privacy policy applies from then on.

Sire & Dam (dog breeding records)

• On your device: dogs, registration details, heats, tests, matings, litters, puppies, weights, care tasks and photos, and the buyers and waiting-list entries you add (names, contact details, deposits and notes).
• Buyers' data: you are responsible for the information you record about buyers. The Service Provider never receives it.
• Camera and photos: used only when you add photos of your dogs and puppies. Reminders are scheduled locally.
• Backup, puppy packs and exports: the backup file, the PDF puppy packs and CSV exports are created on your device and go only where you choose to save or share them (for example Google Drive, iCloud Drive or e-mail). Treat them as private: they can contain buyers' contact details.
• Ads and Pro: on Android the free version shows occasional full-screen ads (see Advertising); Pro removes them. The iOS version will show no ads.

Hatch Day (egg incubation tracker)

• On your device: incubators, clutches, candling logs and photos, temperature and humidity readings, hatch results and statistics.
• Camera and photos: used only when you add candling photos. Reminders for turning, candling, lockdown and hatch day are scheduled locally.
• Reports: PDF reports and CSV exports are created on your device and shared only when you choose.
• Guide pictures (candling and sexing guides) are built into the Application; nothing is downloaded to show them.
• iPhone: the iOS version works the same way, shows no ads, and asks for camera or photo library access only when you add a candling photo.

Nebari (bonsai care), not yet released

• On your device: your trees, care history, notes and photos.
• Hemisphere and climate: used to time seasonal care tasks. The first suggestion comes from your device's region setting; Nebari does not use GPS or your location.
• Backup: the backup file (ZIP) is created on your device and goes only where you choose to save or share it. Restoring reads a file you pick. Treat the file as private: it contains your photos and notes.
• Camera and photos: used only when you add photos of your trees. Reminders are scheduled locally.

Stickwise (drum rudiment trainer), not yet released

• Microphone: used only while you run a timed practice with the microphone on, to detect your strokes and compare them with the click. The sound is analysed in real time on your device and is never recorded, stored or sent. Without microphone access you can still browse the rudiments and listen to them, but timed scoring needs the microphone.
• On your device: practice history, tempos and scores.

Wirepass (electrician exam practice), not yet released

• On your device: your answers, practice and exam results and progress statistics. Nothing else is collected beyond the general sections above.

Cable Calc (electrical calculations)

• On your device: your calculations and saved projects. Results are shared only when you choose to share them.

InvoiceLens (e-invoice viewer), not yet released

• Invoices you open: e-invoice files (such as XRechnung, ZUGFeRD or other PDF and XML invoices) that you open or share into the Application are read, displayed and checked on your device. Invoices often contain names, addresses, bank details and other information about the sender and recipient; this is never uploaded to the Service Provider or anyone else by the Application.
• On your device: a copy of each invoice you keep in the Application, with its key details (number, seller, dates, amount, paid status). You can delete them in the Application.
• Exports are created on your device and shared only when you choose.

How we use information

• To provide the Application's features and unlock purchases you have made
• To show ads in free versions, in line with your consent choices
• To understand usage, fix crashes and bugs, and improve the Application
• To comply with legal obligations and to prevent fraud or abuse

We do not sell your personal information. We do not use the information described in this policy to send you marketing communications.

Legal bases (EEA/UK users)

• Consent: personalized advertising and storing analytics identifiers. You can withdraw consent at any time through Privacy options.
• Performance of a contract: processing your purchases and providing Pro features, and writing listings with AI in Relisto when you ask for it.
• Legitimate interests: crash reporting, restricted (cookieless) analytics measurement, non-personalized ads and security. You may object to this processing by contacting us.
• Legal obligation: keeping records required by tax or consumer law.

Third-party service providers

The services below process data on our behalf or as independent controllers under their own privacy policies. Cloudflare and Anthropic are used only by Relisto, which is not yet released.

We may also disclose information:

• as required by law, such as to comply with a subpoena or similar legal process;
• when we believe in good faith that disclosure is necessary to protect our rights, protect your safety or the safety of others, investigate fraud, or respond to a government request.

International data transfers

Our service providers may process data in countries outside your country of residence, including the United States. Where the law requires safeguards for these transfers, we rely on appropriate mechanisms, such as:

• Standard Contractual Clauses (SCCs) approved by the European Commission
• Adequacy decisions, including the EU-U.S. Data Privacy Framework where the provider is certified
• Other legally recognized transfer mechanisms

Data retention

• Data on your device is kept until you delete it in the Application or uninstall the Application.
• Firebase Analytics user-level data is retained for up to 14 months, then deleted automatically. Aggregated reports that no longer identify you may be kept longer.
• Crashlytics crash reports are retained for up to 90 days.
• Relisto listing server: photos, details and generated text are not stored; monthly usage counts are deleted after 40 days, daily per-IP counts after 2 days, and cached Pro status after 1 hour.
• Advertising data is retained by Google according to its own policies.
• Purchase records are retained by Google, Apple and (where used) RevenueCat as long as needed for the purchase and as required by law.

Your rights

Depending on where you live, you may have the right to access, correct, delete, or receive a copy of your personal data, to restrict or object to processing, and to withdraw consent at any time. Because our Applications do not use accounts, much of the data described here is linked only to random identifiers and not to your name. To help us find your data, please tell us which Application you are writing about.

• Change ad and analytics consent: the Privacy options item in the Application's menu (where shown)
• Delete in-app data: the delete or clear history options in the Application, or uninstall it
• Reset advertising identifiers: your device settings
• Any other request: email [email protected]. We respond within 30 days.

If you are in the EEA or UK, you also have the right to lodge a complaint with your local data protection authority.

Your California privacy rights (CCPA/CPRA)

If you are a California resident, you have the right to know what personal information is collected, the right to delete it, the right to correct it, the right to opt out of the sale or sharing of personal information, and the right to non-discrimination for exercising these rights. We do not sell personal information for money. Showing ads through AdMob may count as "sharing" for cross-context behavioral advertising. You can opt out through Privacy options in the Application (where shown), by turning off ad personalization in your device settings, or by contacting us at [email protected].

Children

Our Applications are not directed at children under 13, and we do not knowingly collect personal information from them. In countries where the age to consent to data processing is higher (up to 16 in some EEA countries), a parent or guardian must make any consent choice the Application asks for, such as for personalized ads. If you are a parent or guardian and believe your child has provided personal information through an Application, please contact us at [email protected]. We will take steps to delete it.

Security

Data sent by our third-party services is encrypted in transit (HTTPS/TLS). Data kept on your device is protected by your device's own security features, so we recommend keeping a screen lock enabled. No method of transmission or storage is completely secure, but we work to protect your information.

Data breach notification

If a data breach affects your personal data, we will notify you and the relevant authorities as required by applicable law.

Changes to this policy

We may update this privacy policy from time to time. We will post the updated policy on this page with a new effective date. For material changes, we will provide additional notice where required by law. Previous versions are available on request.

Summary of changes in this version (2026-11-02)

• Sire & Dam is now released on Google Play: moved to the published Applications, added its Android ads, backup and export details
• Corrected the list of Applications that use RevenueCat (all Flutter-based Applications; MultiTimer and Shadow Match use Google Play Billing directly)

Changes in the version of 2026-10-20

• Stated that on iPhone and iPad, Firebase Analytics always runs in restricted mode without storing analytics identifiers, because the iOS versions have no consent form

Changes in the version of 2026-10-18

• Smart Quiz became Trivia Showtime: questions are now built in (no download from opentdb.com), host voices use your device's text-to-speech, and we describe the question analytics and reporting a question by email
• Rhythm Trainer: added Daily Chart, Timing Coach (on-device analysis) and the related usage events
• Hatch Day: added the iOS version and the built-in picture guides
• Stated that iOS versions show no ads and do not use the Apple advertising identifier, and that free versions show only occasional full-screen ads, no banners
• Updated the RevenueCat and Open Trivia Database entries in the service provider list

Changes in the previous version (2026-10-17)

• Added app-by-app details for Rhythm Trainer, Smart Quiz, Steady Hand, Shadow Match, ZeroMargin, Days Until, MultiTimer and Daily Budget
• Added the Open Trivia Database (Smart Quiz questions) as a service provider
• Stated which Applications show ads, and marked Applications that are not yet released
• Clarified the minimum age and parental consent

Changes in the version of 2026-10-09

• Added app-by-app details for Endly, Relisto, Sweet Ledger, Sire & Dam, Hatch Day, Nebari, Stickwise, Wirepass, Cable Calc and InvoiceLens
• Described the Relisto listing server, and added Cloudflare and Anthropic as service providers
• Stated that Endly has no ads, analytics or crash reporting and keeps health entries on your device
• Added retention periods for the Relisto listing server

Changes in the version of 2026-10-03

• The policy now covers all MintWave Studio apps (the previous version named only Steady Hand)
• Added Firebase Analytics, Firebase Crashlytics, purchases (Google Play Billing, Apple App Store, RevenueCat) and in-app review
• Explained the consent form and the in-app Privacy options
• Added on-device camera text recognition (Days Until), local notifications and on-device data storage
• Updated retention periods, legal bases and the list of service providers

Contact us

If you have any questions about privacy in our Applications, please contact MintWave Studio at [email protected].