Privacy Policy

Maelzel · Effective date: September 14, 2026 · Last updated: November 3, 2026

Maelzel (bundle identifier xyz.bogtsi.maelzel) is made by Bogdan Tsiganiuk, an individual developer. Contact: bogdan.tsiganiyk@gmail.com.

The short version: Maelzel has no account, no sign-in and no server of ours. Your songs, setlists, pieces and practice sessions are stored locally, not uploaded by purchase or update checks. You can export them, and your operating system may back them up. Apple and RevenueCat process purchase-related information, including automatic access and unlock status checks at startup even if you do not start a purchase. Expo may automatically check for and download app updates.

What we collect

Your practice records stay in local app storage; Maelzel does not upload them to us. This is different from the third-party service traffic described below: Apple and RevenueCat process purchases and entitlement checks, and Expo provides app updates. These services can receive requests automatically, not only when you tap Buy or Restore. There is no analytics SDK, no advertising SDK, no crash reporter that carries your data, and no identifier for advertisers (IDFA). We do not ask for tracking permission because we do not track.

What stays on your device

Your songs: the name you gave each one and the tempo, meter, accents, subdivision, sound, count-in and notes saved with it.
Your setlists: their names, the order of the songs in them, and the gap between songs.
Your pieces: their names, and the ladder history filed against each one.
Your practice sessions: when you played, for how long, in which mode, at which tempos, and how a ladder ended.
Your settings: count-in, keep-awake, visual lead, haptics, flash, volume and the last program you had loaded.

All of it is written to your device’s local app storage (on iOS, via Apple’s on-device storage APIs — this app uses no cloud database of its own). Deleting the app removes these local records; exported files and operating-system backups are managed separately.

Data sharing and service requests

You export a file. Tapping Export backup in Preferences → Data builds a JSON file and hands it to the iOS share sheet. Where it goes from there is your choice — Files, iCloud Drive, Mail, another app. We are not involved and we receive no copy. Import backup reads a file you pick with the system document picker; the picker only ever sees the one file you choose.
iCloud device backup. If you have iCloud Backup switched on in iOS Settings, your device’s backup includes this app’s data, the same as any other app. That is Apple’s service under Apple’s terms, not ours. Maelzel does not implement its own sync.
Trial, lifetime purchases, restores and access checks. Apple handles purchases and restores, and RevenueCat manages purchase state for us. The app automatically checks access at startup, even if you have not initiated a purchase; cached information may be used when available. Current offerings and fresh purchase information require network access. Apple processes payment; we never see payment details. RevenueCat receives an anonymous app-user identifier and purchase receipt information to establish the original free-trial purchase date or lifetime ownership. The free trial lasts 72 hours, requires explicit start and never automatically charges; continued metronome and trainer use afterwards requires a separate one-time lifetime purchase. These checks do not upload songs, setlists, pieces or practice logs. RevenueCat’s privacy policy: revenuecat.com/privacy
Automatic app updates. Maelzel is configured to use Expo’s update service at https://u.expo.dev. It may automatically send technical update-service requests and download available app updates. These are requests for app updates, not uploads of your songs, setlists, pieces or practice log. Expo’s privacy policy: expo.dev/privacy

Sound out, never sound in

Maelzel plays a click. Every click sound is synthesised on your device at the moment it is played — click audio is not downloaded or streamed. The app has no microphone access: there is no tuner, no recording, no pitch detection and no beat listening anywhere in it, and it never asks for microphone permission, so iOS never shows that prompt. The app includes a microphone purpose string only because Apple requires one whenever an included audio library contains recording code that the app does not use. It has no camera access either.

Why the app can play in the background

Maelzel declares the iOS background audio capability. That is what lets the click keep going when you lock the screen or switch apps — a metronome that stops the moment your phone sleeps is no use on a music stand. It is used for the click and nothing else: the capability does not give an app access to the microphone, to your location, or to anything you are doing in other apps.

Permissions we never ask for

Maelzel does not request microphone, camera, photo library, notification, location, contacts or Health permissions. Export and import open the system share sheet and document picker when you choose those actions. Apple may also show system purchase or restore interfaces, including the purchase confirmation sheet.

Children

Maelzel is not directed at children. Practice records remain local as described above; the purchase and update services described in this policy may still process service requests.

Your rights

You can export local practice records using Export backup and remove local records by deleting the app. Expiry does not delete records or prevent export. Manage exported copies and operating-system backups separately. Deleting the app does not delete purchase records held by Apple or RevenueCat or restart the trial. For questions or requests about provider-processed information or support correspondence, email bogdan.tsiganiyk@gmail.com. Provider-held information is also subject to provider privacy policies and rights-request processes.

Changes

If this policy changes, the date at the top changes with it, and the link in the app’s Preferences → Support & legal points at the current one.