Guide Tones

Guide Tones Privacy Policy

Last updated: 6 November 2026

Guide Tones: Jazz Ear Training (“Guide Tones”) is an ear-training app for jazz musicians. This policy explains what information Guide Tones uses, where it goes, and the choices you have. We have tried to keep it short and in plain English.

Who we are

Guide Tones is run by Matthew James Hammond, trading as Guide Tones, based in Spain. We are the “controller” of the personal information described below. You can contact us at matthewhammond@outlook.com.

The short version

  • You do not need an account to use Guide Tones, and we do not ask for your name or email address.
  • Guide Tones has no adverts and no analytics or tracking tools.
  • When a drill listens to you, the sound is analysed on your phone and never leaves it.
  • Your progress, streaks and settings are stored on your phone.
  • A small amount of information is handled by two services we use: one for purchases, and one for crash reports.

What stays on your device

Guide Tones stores the following on your device only, in the app’s own storage:

  • your practice progress, scores, levels, streaks and points
  • your settings (for example your chosen instruments, chord speed and difficulty)
  • whether you have finished the intro and the placement check
  • your reminder settings, if you switch reminders on

We do not receive any of this. If you delete the app, it is removed with it. Depending on your phone’s backup settings, your phone maker (Apple or Google) may include it in your device backups.

The microphone

Some drills ask you to sing or play your answer, and Guide Tones uses your microphone to listen. Guide Tones asks for permission first, and you can say no or turn the permission off in your phone’s settings at any time. Most of the app still works without it, because you can answer with the on-screen buttons.

  • The microphone is used only while a drill that needs it is open and listening is switched on.
  • Sound is analysed on your device to work out which notes you played. It is not uploaded, shared or kept.
  • For some drills the app saves a short recording of your attempt to a temporary file on your phone so it can analyse it. The file is deleted as soon as the analysis finishes.

Reminders and notifications

If you switch on practice reminders, Guide Tones asks for permission to show notifications. The reminders are scheduled on your phone. They do not use any server, and we do not send push notifications from our systems.

Purchases

Guide Tones is free to use, with a one-time purchase that unlocks Pro content. Payments are handled by Apple or Google. We never see your card or payment details.

To confirm what you have bought and unlock Pro on your devices, Guide Tones uses a service called RevenueCat (RevenueCat, Inc.). When the app starts, and when you view the purchase screen, buy, or restore purchases, RevenueCat receives:

  • a random identifier for the app installation (not your name or email)
  • your purchase and Pro unlock status
  • basic technical information such as your device type, operating system version, app version, language and region, and your IP address

RevenueCat acts as our data processor and uses this only to provide the purchase service to us. RevenueCat is based in the United States and stores data there, so your information may be transferred outside the European Economic Area (EEA). Our data processing agreement with RevenueCat includes the European Commission’s Standard Contractual Clauses to protect it. You can read how they handle information at revenuecat.com/privacy-policy.

Crash reports

If Guide Tones crashes or hits a serious error, it can send a report to a service called Sentry so we can find and fix the problem. A report can include:

  • what went wrong, including the technical error message and where it happened in the code
  • your device model, operating system version and app version
  • the order of recent actions in the app that led up to the problem
  • your IP address, which Sentry’s servers receive when the report arrives (our Sentry account is set not to store it)

Sentry also receives a small, anonymous record of each time the app is used: that it was opened, for how long, and whether it ended in a crash. We use this only to see how many sessions end in a crash, so we can tell whether an update has made the app more or less reliable.

To do this, Sentry gives each installation of the app a random identifier. It is not your name, your email, your Android ID or your advertising ID, and a new one is made if you reinstall the app. It lets Sentry count how many installations a problem affects and what share of them are free of crashes.

Reports do not include your name or email, because Guide Tones does not collect them. Our Sentry account stores data in the European Union (Germany).

  • To run the app and deliver the Pro purchase you asked for: this is needed to carry out our contract with you.
  • To find and fix crashes and keep the app working: this is our legitimate interest in running a reliable app. We keep what we collect to the minimum.
  • Microphone and notifications: we rely on your permission, which you can withdraw in your phone’s settings at any time.

Who we share information with

We do not sell your information, and we do not use it for advertising. We share it only with:

  • RevenueCat, to provide purchases and Pro unlocks, and Sentry, to provide crash reports
  • Apple or Google, who run the app stores and process your payments under their own privacy policies
  • the authorities, if we are legally required to

How long we keep it

  • Information on your device stays there until you delete the app or clear its data.
  • Purchase records at RevenueCat are kept for as long as we use their service to confirm your purchase, or until you ask us to delete them. RevenueCat may keep limited records for longer where the law requires.
  • Crash reports are kept for 90 days.

Your rights

Under the EU’s General Data Protection Regulation (GDPR) and Spanish data protection law, and under similar laws elsewhere, you can ask us to:

  • tell you what information we hold about you, and give you a copy
  • correct or delete it
  • restrict or stop us using it

Because Guide Tones has no accounts, we cannot tell who you are from the app alone. To make a request, email matthewhammond@outlook.com and include your App Store or Google Play order number, so we can find your purchase record. We will reply within one month.

If you are unhappy with how we handle your information, please contact us first so we can try to put it right. You also have the right to complain to the Spanish Data Protection Agency (Agencia Española de Protección de Datos, AEPD) at aepd.es, or to your local data protection authority.

Children

Guide Tones is not aimed at children under 14, and we do not knowingly collect information from them.

Security

Information sent between the app and the services above is encrypted in transit. Information stored on your device is protected by your phone’s own security. No system is perfectly secure, but we only use the services described here and we collect as little as we can.

Changes to this policy

If we change how Guide Tones handles information, we will update this page and the “last updated” date. If a change is significant, we will tell you in the app.

Contact

Matthew James Hammond, trading as Guide Tones
matthewhammond@outlook.com

If you email us, we use your email address and message only to reply to you. If you join the Android beta, we also use your Google account email address to add you to the tester list in Google Play, and we delete it from our records when the beta ends.