The classic board game Stratego is now a free-to-play game online and a paid app on iPad. Developed by Dutch studio Keesing Games, the three versions across web, Facebook and iPad are cross-compatible. The game also supports the classic 40-piece version, along with a "blitzkrieg" 10-piece game.
If you've never played Stratego, the game revolves around capturing the other team's flag. As General Izzard explains, this is how lands are conquered. Players place their two armies, which include special units like bombs and the spy (needed to kill the best unit on the field), then try to outmaneuver each other without losing their best units.
The iPad app is $6.99, while the Facebook version and the one at www.stratego.com are free. If you want to go original gangster, the board game is $25.