Developer Jellyvision is best known as the company behind the great You Don't Know Jack series -- they've made nearly every version of the best-selling trivia video game, including the really great iOS iteration. Lie Swatter is the latest game from the company, and while it's not related to You Don't Know Jack, it is still a trivia game in the vein of fast, fun, multiplayer action that YDKJ does so well.
The idea here is that you're given a number of statements in the form of cartoon flies, some of which are true and some of which aren't. It's your job to try and smack down as many lies as you can, while leaving the truths alone. Games can be played against Facebook friends, Game Center friends or just random opponents, and you basically pass turns back and forth, each trying to swat more lies than your opponent.
Personally, I don't really like Lie Swatter as much as Jellyvision's other work -- I much prefer YDKJ's multiple choice format, and the fact that you can sit down and play a game through without having to wait for turns to return. But Lie Swatter is a fun title, and I can see how its more casual gameplay might appeal to some players, especially if you've got willing friends to play along with. It's available on the App Store for free right now, and though there are ads in the app, you can pay a $1.99 in-app purchase to remove them completely.