I've been playing Alpha Chess for quite some time. It's a simple but nice chess game. Unfortunately the AI is quite simple as well. Beating it on "Expert" mode doesn't take an expert. The Multiplayer mode might be the solution but finding other players is next to impossible, most likely because few people know Alpha Chess to begin with.

Just awesome! This is the best chess board application I ever saw, so pretty and easy to use and yet gives you so much options.