Mindfret

Privacy Policy

Last updated 28 September 2026. Applies to the Mindfret iOS app and this website.

Who is responsible

Mindfret is made by Denis Surchenko, an independent developer, who is the data controller for the small amount of data described here.

Questions, objections or requests: support@mindfret.com.

What stays on your phone

Your progress is held in the app's own private storage, the part of your phone only Mindfret can read. It contains:

• every note, interval, chord grip and scale degree the app has asked you, and how quickly you answered;
• which drills you have done and what is due next;
• your settings, and a note of whether Mindfret Pro is unlocked.

There is no server the app reads from and nothing to sync, which is also why every drill works with the phone in aeroplane mode. The usage events below include your answer times, but they are a one-way report: nothing is ever read back into the app. Deleting the app deletes your progress, and there is no copy anywhere else. If your phone backs itself up to iCloud, Apple's backup may include the app's storage, under Apple's terms rather than ours.

What is sent, and why

Mindfret sends anonymous usage events. They exist to answer questions we cannot otherwise answer about the app itself: whether people come back, where a drill stalls, and whether the speeds the app grades you against are set anywhere near right for real players rather than for the author.

An event may carry:

• when a session started and finished, which tab it was on, whether it was played in a key and which scale, how many sessions you have done so far, the session length you have chosen, and how much of the material you have opened;
• the answer times from that session, whether each answer was right, and which item each one was (a fret and string, an interval shape or a chord grip), with no note of who answered;
• when a new batch of material opened, or an item first turned green;
• when a tab's rank went up, and how many days in a row you have finished a session;
• whether Mindfret Pro is unlocked, when the Pro screen was shown and what opened it, and whether a purchase or a restore went through;
• your app version, iOS version, device model, and language and region setting, which are attached automatically.

Every event is tagged with a random identifier generated on your device the first time the app runs. It is not your Apple ID, not your device's serial number and not an advertising identifier. It identifies an install, not a person, and it is not joined to anything else. Reinstall the app and a new one is generated, with no way to connect the two.

This is processed for us by PostHog on their European cloud (eu.i.posthog.com), so the events are stored in the EU. As with any request over the internet, PostHog receives the IP address the request came from; it is used to work out an approximate country and is not used to identify you.

What we have deliberately switched off

• No identify call, so no profile is ever built for a person.
• No session recording or screen replay.
• No automatic capture of taps and screens. Only the events listed above are sent, and each was chosen one at a time.
• No advertising identifier and no App Tracking Transparency prompt, because there is nothing here to track you with.

Turning it off

Settings, behind the gear at the top of the home screen, has an option called Anonymous usage data. Untick it and the app stops sending. Anything not yet sent is deleted from the phone rather than sent later. Nothing else in the app changes.

Buying Mindfret Pro

Mindfret Pro is a single payment, handled entirely by Apple. Your card details go to Apple and never to us; we never see them.

To know whether you have bought it, including on a new phone when you restore your purchase, the app uses RevenueCat, Inc. (United States), which receives the App Store transaction along with an anonymous identifier for the install. No name or email is attached. Because RevenueCat is outside the EEA and the UK, that transfer relies on the European Commission's standard contractual clauses.

What Mindfret never collects

• Your name, email address, phone number or date of birth.
• Your contacts, photos, calendar, microphone or camera. The app requests none of these permissions.
• Your location. There is no GPS, and no request for it.
• An advertising identifier, or anything else usable to track you across apps and websites.

There are no adverts in Mindfret, and no data about you is sold or shared for anyone else's marketing.

How long anything is kept

Usage events are kept for as long as they are useful for the questions above, and no longer than 24 months, after which PostHog deletes them. What is on your phone stays there until you delete the app or reset a tab in Settings.

Your rights

If you are in the EEA or the UK, the law gives you rights over personal data about you: to see it, correct it, have it deleted, and to object to how it is used. The legal basis for the usage events is our legitimate interest in understanding whether the app works, and the option in Settings is the right to object made straightforward, with no email required.

One honest limitation, required to be stated: because the events carry no identifier we can link to you, we normally cannot find yours in order to show or delete them, and we will not ask you for extra information just to make you identifiable to us. Turning the option off stops any further collection, which is the part that is fully in your hands. If you believe we have handled data badly, you may complain to your national data protection authority.

Children

Mindfret contains nothing unsuitable for any age, but it is written for people who already play the guitar and is not directed at children. It collects no personal information from anyone, of any age.

Changes to this policy

If what the app does changes, this page changes with it and the date at the top moves. Nothing already collected is repurposed under a new version.