Privacy policy of the “TonStrom” app
Last updated: 9 October 2026 · applies to the Android app TonStrom (de.christiankempf.tonstrom). The website is covered by the general privacy policy. In case of doubt the German version prevails.
In short: TonStrom only connects your phone to devices on your own Wi-Fi. The sound goes straight to the speaker and is stored nowhere. There is no account, no server, no internet connection and no advertising.
1. Controller
Christian KempfBreitenweg 2, 72406 Bisingen, Germany
E-mail: christian.firmdev@gmail.com
2. Connections only on your own Wi-Fi
TonStrom searches your Wi-Fi for speakers, receivers and TVs, controls them directly and provides the sound to them as a stream within your home network. The app makes no connection to servers on the internet, including mine. What the speaker itself does with its data is up to its manufacturer.
3. Your phone’s sound
For “phone audio”, TonStrom uses Android’s playback capture: each time, Android asks whether the app may share the screen. Only the sound played by other apps is used – never the picture and never the microphone. The sound is not recorded or stored, only passed on in real time to the chosen speaker. A notification shows while streaming is active.
4. What the app stores
- Paired speakers: name, address in the home network, remembered audio format and delay.
- Settings: for example whether the phone is muted while streaming.
- Log: technical messages of the current session for troubleshooting; they stay on the device.
5. Permissions
| Network | Finding and controlling speakers on your Wi-Fi, providing the stream (see 2) |
|---|---|
| Record audio | Required by Android for playback capture; the microphone is not used (see 3) |
| Foreground service “screen sharing” | So streaming continues while you use another app; only the sound is used |
| Notifications | Showing the running stream with “Stop” |
| Keep awake | So the stream doesn’t stop when the screen is off |
6. No advertising, no analytics
TonStrom contains no advertising, no analytics tools, no trackers and no crash reporting.
7. Retention and deletion
Data stays on your device until you unpair a speaker or uninstall the app. Android may include app data in your personal device backup if you have enabled this in the system settings.
8. Your rights
As I receive no data from the app, I cannot provide information about it or delete it; you have full control on your device. For questions, contact me at the address above. You may also lodge a complaint with a data protection supervisory authority, for example the one responsible for me: the State Commissioner for Data Protection and Freedom of Information Baden-Württemberg, Lautenschlagerstraße 20, 70173 Stuttgart, Germany.