Last Updated: September 30, 2026
This policy covers one app: Practice Proof, the music practice log, on Android, iPhone and iPad. Our other apps are covered by the general Illumination Development privacy policy, which does not apply here. That policy describes reward balances and redemption records that this app does not have.
The short version
The microphone is used only while a practice session is running, and nothing is recorded. Each second of sound is analysed on the phone, the app keeps only the answer to one question (was an instrument or singing heard?), and the sound itself is thrown away. No audio is saved, and none is sent anywhere.
There is no account. The practice log (the players you add, their sessions and notes, their goals and your reminder settings) is stored on the phone and nowhere else. We never receive it.
What does leave the phone is advertising, usage analytics and crash reports, described in full below. Every advertisement request is marked as child-directed, rated G and not personalised.
The microphone
The app asks for the microphone the first time you start a session, after a screen that explains why. While a session is running, the operating system's own sound classifier analyses the sound in windows of about one second: on iPhone and iPad, Apple's built-in SoundAnalysis classifier; on Android, a sound classification model (YAMNet) that ships inside the app. Both run entirely on the phone and use no network.
For each window the app keeps one fact, whether practice was heard, and uses it to count the seconds of practice. It keeps no recording, no transcript, no list of what else was heard and no audio of any kind, and it never sends sound anywhere. When you pause, finish or leave the session, the microphone is turned off. The app does not listen at any other time, and it does not listen in the background.
One limit, stated honestly: music played through a speaker sounds like practice to the classifier, so it counts too. The app cannot tell who is playing, only that music is.
What stays on the phone
Everything you enter: player names, instruments and daily goals; every session, with the minutes heard, the time it lasted, the day, whether you added it by hand, and any note; and your reminder time. It is stored in the app's private storage and is removed if you use Delete my data or uninstall the app. Reminders are scheduled on the phone by the operating system; no server sends them.
Practice sheets (PDF or spreadsheet) are made on the phone and handed to your phone's share sheet. Where they go next is your choice; the app keeps no copy.
What the app sends
None of what follows includes a player's name, a note, the minutes of any one session or any sound.
Usage analytics
The app reports a small set of events to Google Analytics: which screen is open; how long the app took to start; that a listening session was kept, with its heard minutes rounded into a range (0–4, 5–14, 15–29, 30–59 or 60 and over) and whether the day's goal was met; that a session was thrown away; that a session was added by hand; that a player was added, and which instrument they play; that reminders were turned on or off; that the walkthrough was finished; that a practice sheet was exported, as PDF or spreadsheet, and for which span (a week, four weeks or a year); that the privacy policy was opened; and when an error message was shown.
Alongside those, Google Analytics collects its own app-instance identifier, coarse device information such as the model, the operating system version and the app version, and an approximate location that Google derives from the IP address. The app itself never asks for location. We use analytics to see which parts of the app are used, and for nothing else.
Crash and diagnostic reports
If the app crashes or hits a handled error, Google Crashlytics sends a report: the stack trace, the app version, the device model and operating system, and Crashlytics' own installation identifier. This is how bugs get found. Analytics and crash reporting are both switched off in development builds.
Advertising
The app is free and carries advertising from Google AdMob and no one else. There is one placement: a banner on the home screen. There is never an advertisement on the listening screen, there are no full-screen or rewarded advertisements, and there is nothing to buy.
Because a phone running a practice session is often in a child's hands, every advertisement request is marked as child-directed (Google's treatment for child-directed content), limited to content rated G, and not personalised. The app does not show Apple's tracking prompt and does not request Apple's Identifier for Advertisers. To serve a banner, the Google Mobile Ads SDK contacts Google and may collect device information, an approximate location derived from the IP address, and the request, impression and click themselves, under Google's own privacy policy. We never see any of it, and none of it is connected to your practice log.
On Android, the Google Mobile Ads SDK declares the advertising-ID permission; the child-directed setting tells Google not to use it for personalised advertising. You can reset or delete your advertising ID in your phone's settings.
In the EEA, the UK and Switzerland
Where a consent regime applies, Google's consent message is shown before any advertisement is requested, and the app asks as if the user may be under the age of consent. Settings → Ad privacy options reopens the same choices at any time; that entry appears only where a consent regime applies.
Contacting support
Settings → Contact support opens your own email app, addressed to support@illuminationdevelopment.com. The app attaches nothing: what we receive is exactly what you write, from the address you send it from, and we use that address only to reply.
Delete my data
Settings → Delete my data immediately erases every player and every session from the phone, with their notes, goals and your reminder settings, and resets the Google Analytics identifiers held on the phone. Pending reminders are cancelled as the app reloads its now-empty log. There is no copy anywhere else for us to delete, and no audio ever existed to delete.
Analytics events and crash reports already sent to Google before you pressed it are kept by Google under its own retention periods, keyed to identifiers that no longer lead back to this installation. To ask about those, write to privacy@illuminationdevelopment.com.
What the app does not do
- No recording. Sound is analysed as it happens, on the phone, and discarded.
- No listening outside a running session, and none in the background.
- No account, no sign-in, and no upload of your practice log.
- No in-app purchases, no rewards and nothing for sale.
- No chat, no sharing with other users, and no way to reach another person through the app.
- No location permission, and no access to contacts, photos, files, calendar or health data.
- No advertising network other than Google AdMob, and no personalised advertising.
- We do not sell personal information.
Children
Practice Proof is meant to be set up and managed by a parent or guardian, often for a child who is learning an instrument. The names a parent enters for players stay on the phone and are never sent to us or to anyone else. Because children may use the phone during a session, advertising is child-directed and non-personalised as described above, and the only information that leaves the phone is the analytics and crash reporting described here, none of which includes a name or any sound. If you believe a child has sent us personal information, for example in an email, write to privacy@illuminationdevelopment.com and we will delete it.
Your rights
Under the GDPR, the UK GDPR, the CCPA and CPRA, and comparable laws elsewhere, you have rights to access, correct, port and delete personal information held about you. Your practice log is on your phone, where you can export it as a practice sheet and erase it with Delete my data. For anything else, including a support email or data Google holds from analytics, crash reports or advertising, write to privacy@illuminationdevelopment.com. Information Google holds from running those services is subject to Google's privacy policy.
A note about this web page
The app does not display this page; tapping Privacy Policy in Settings opens it in the phone's browser, and this website uses Google Analytics to see which pages people find useful. That is described in the general policy and applies to your visit to this page, not to your use of the app.
Changes to this policy
If any of this stops being true, this page changes before the version that changes it reaches either store, and the App Store privacy label and Google Play Data safety form change with it. Revisions are posted here with an updated date.
Contact
Email: privacy@illuminationdevelopment.com
You can also reach us through our contact and support page.