UI: Explain why Rethink needs "nearby devices" permission

[ignoramous]

User1: Might i ask why is now asking for Nearby Devices permission? Pixel 10a

...

User2: This also surprised me. and my family almost just disabled rethink due to it. The app should definitely explain why it's using it since the OS description of Nearby Devices doesn't mention access local network at all.

Android 17 support required Rethink to ask for the new ACCESS_LOCAL_NETWORK permission for WireGuard, mDNS, and other proxy forwarding features.

[vectorwren]

Simple answer to the question: Rethink routes some traffic over your local network, and Android 17 requires a permission for that.
Concretely, three things Rethink does need local-network access:

• WireGuard / proxy tunnels to a home server or router: the tunnel endpoint is a device on your LAN
• Resolving local hostnames (mDNS-style names like printer.local)
• The "Do not route Private IPs" / LAN-routing features: talking to devices on your own Wi-Fi without sending that traffic through the tunnel
  On Android 17 the OS gates all of that behind the new ACCESS_LOCAL_NETWORK permission. The catch, and the reason this issue exists, is that the Settings UI calls it "Nearby devices", and its description talks about Bluetooth-adjacent things. Same permission, misleading label: for Rethink it means local network access, nothing more. No Bluetooth, no scanning, nothing leaves your Wi-Fi.
  What would fix the confusion (happy to PR):

1. Show a short explainer before the system prompt appears, including the sentence "the permission will be labeled 'Nearby devices'; for Rethink it means local network access", so the two screens connect.
2. Add the same "listed as Nearby devices" note to the existing post-denial dialog, so people who hit Settings know which row to grant.

[pingu-the-penguin]

It is my understanding that the features that RethinkDNS offers that would require Nearby Devices permission are optional (as the VPN service, in-app Wireguard proxy and DNS handling) work just fine in my case after I revoke the permission soon after the VPN service is started. In that case, I think making it possible to dismiss the pop-up and not forcing users to grant the permission would be beneficial.