Privacy policy of the “RudelLink” app
Last updated: 15 November 2026 · applies to the RudelLink Android app (de.christiankempf.homereach). The website is covered by the general privacy policy. The German version is legally binding.
In short: RudelLink only connects your phone to your FRITZ!Box and your own devices. Credentials and keys are stored encrypted on your device. There is no account, no server and no advertising.
1. Controller
Christian KempfBreitenweg 2, 72406 Bisingen, Germany
E-mail: christian.firmdev@gmail.com
2. Everything stays on your device
RudelLink has no user account and sends no data to me or to third parties. Everything you create in the app is stored on your device only:
- Device list: name, address, port and path of your devices and your settings for them, in the app’s storage.
- Credentials: user name and password for automatic login, encrypted in the Android Keystore.
- WireGuard configuration: including the private key, encrypted in the Android Keystore.
- Browser data: your devices’ web interfaces open in a built-in browser. Like any browser, it may keep cookies and cached pages in the app’s storage.
3. Connections the app makes
RudelLink is a tool for connections you set up yourself. The app only connects to
- the VPN endpoint in your WireGuard configuration, usually your FRITZ!Box, and
- the addresses of the devices you add to the list.
Which traffic runs through the tunnel, only traffic to your home network or all your internet traffic, is defined by your FRITZ!Box configuration. What your devices and your FRITZ!Box process themselves is governed by their manufacturers. I receive nothing from these connections.
Tunnel settings: If you enter your own DNS servers, name lookups in the tunnel go to those servers. To choose excluded apps, RudelLink reads the list of apps on the phone; it stays on the device.
Recognising the home network (optional): If you save your Wi-Fi as the home network, RudelLink reads the name of the connected Wi-Fi to decide whether a tunnel is needed. Android only reveals the Wi-Fi name if the app is allowed precise location and location is switched on. RudelLink does not request or store your position; only the name of the home Wi-Fi is stored.
RudelLink is not a product of FRITZ! GmbH and has no affiliation with it.
4. QR code scanning
The app recognises your FRITZ!Box QR code on the device using Google’s ML Kit library. Camera images are neither stored nor transmitted. Google states that ML Kit may send technical information such as device model, app name and performance data to Google to operate and improve the service. To avoid this, you can pick the configuration as a file or paste it by hand instead.
5. Permissions
| Internet | Connection to the FRITZ!Box and to the devices in your list (see 3.) |
|---|---|
| VPN | Setting up the WireGuard tunnel. Android asks for your consent once when you first connect. |
| Location (optional) | Only to read the name of the connected Wi-Fi (recognising the home network, see 3.); Android requires location for this. Positions are not requested. |
| Wi-Fi state | Detecting whether the phone is on Wi-Fi or mobile data |
| Camera (optional) | Only for scanning the QR code, only while the scanner is open. |
| Biometrics (optional) | For the app lock. Android performs the check; the app receives no biometric data, only the result. |
| Notifications | Showing the running tunnel with a “Disconnect” button. |
| Files (when needed) | Importing a configuration and exporting or importing the device list through the Android file picker. The app has no permanent access to your files. |
6. No ads, no analytics
RudelLink contains no advertising, no analytics tools and no trackers. No advertising ID is read.
7. Export
The device list export contains names, addresses and settings only, deliberately no passwords and no WireGuard configuration. Where you store or send the file is up to you.
8. Retention and deletion
Data stays on your device until you delete it in the app or uninstall the app. Android may include app data in your personal device backup (e.g. your Google account) if you have enabled this in the system settings; the credentials and keys encrypted in the Keystore cannot be restored from it.
9. 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: Der Landesbeauftragte für den Datenschutz und die Informationsfreiheit Baden-Württemberg, Lautenschlagerstraße 20, 70173 Stuttgart, Germany.