Go program that would allow start playing Go without even reading rules. Animations would 'explain' liberties and solidly connected units of stones by flashing them for a short time after move. Especially combined with touch screen should allow even 2-3 year old children to play Go against computer. Player only need to be able to touch at screen at point (s)he wants to place stone. Phone would then reply and wait for another touch (move). Probably player would eventually figure out what is happening without any explanation. Computer opponent would start close to random strength and increase strength gradually as player increases in strength.
Also maybe add online support using Dragon Go Server. This would allow interruption of games anytime and continuing play later.