Orbot has no obvious leaks I know of right now, and this can be further enforced by using the “Block connections without VPN” system setting.
Using the VPN function is directly what makes it so robust.
Orbot on iOS does have issues, but it is very reliable on Android.
Orbot in full device VPN mode with block connections enabled in system settings and additionally I’d recommend enabling the Tor isolation options in Orbot settings:
- Isolate destination addresses
- Isolate destination ports
- Isolate client protocls