Twitter-based game from iList — Spymaster
playspymaster.com
playspymaster.com
Whats really funny is the question about people with a "Director" level title who are apparently developers or close friends of the game. The answer contains this:
"Directors are playing characters of Spymaster just like you — however, be advised that plotting assassinations against directors may have dire consequences."
But to be honest I made a twitter game a while ago with a friend just to mess with the twitter api, its called BattleBird: http://battlebird.com/