This is NOT an application in and of itself-- you must also install WeGoIgo or WeGoIgo Lite (See other applications by me). After installing both this and a version of WeGoIgo, run WeGoIgo and create a new game. When you choose a player, GnuGo should show up with an Android icon. Click that to choose it as your opponent. Easy!
Note that WeGoIgo doesn't support setting an AI against itself. It won't stop you, but the game probably won't go anywhere.
This is a GnuGo port for use with WeGoIgo. Based loosely on Andreas Grothe's modifications for the NDK part. The source code for this AI is GPL (based on GnuGo) and available on request.
Please contact me if you have any problems!