see https://blog.torproject.org/blog/tor-android
search for torrc and you will find someone who did it by modifying the apk
On May 7th, 2011 Anonymous said:
I figured out how to deploy Orbot with a custom torrc file, without having to rebuild Orbot from source, and without needing a rooted phone:
1. Download the latest Orbot apk file.
2. Open/extract the apk (it's really just a zip file with a different file extension) with your favorite zip utility.
3. Remove the META-INF folder from the apk.
4. Open the torrc file in the assets/ folder and modify it as you like.
5. Zip it all back up again.
6. Sign the .apk file using keytool and jarsigner according to the instructions at this URL: http://developer.android.com/guide/publishing/app-signing.html#cert
7. Copy to phone and install.
Works like a charm. Tested by specifying strict exitnodes and am now successfully watching the BBC iPlayer on my phone even though I'm in the UK.
You can't edit the torrc on the fly or without reinstalling Orbot using this method, but you don't need a rooted phone and you don't risk getting your torrc file overwritten by the old "default" one by Orbot.
On May 23rd, 2011 Anonymous said:
I used this hint to set up Orbot using a http(s)proxy.
It Works !
Nevertheless there should be an option to to that. Perfect were, if this options would map to SSIDs or BSSIDs so it could change automatically if the device is connected to another network.
Thx for the hint.
Milraun