Checkout backstabbr. It's a web based version of the game and allows a lot more asynchronous playing. It also allows you to remain anonymous which helps with biases and super judicial alliances.
For those on Android, check the conspiracy app. It includes about half a dozen variants as well, ranging from 2 players (cold war) to 15 (known World 901). Great platform to play.
It uses the more old-school webdiplomacy interface but I'm fine with the dropboxes.