Interactive Smart Phone Apps Thread

Every week I seem to either make or want to make one of these threads, so I'll just make a lump-sum thread.

Here are some really awesome interactive apps that are either for games or messaging that I want you guys with smart phones to download so we can play together

iPhone/iTouch (with wi-fi)

Words with Friends (Best Scrabble internet version for a phone ever)

All Smartphones -

Kik Messenger (Extremely fast instant messenger system. I love it)

Do you guys have any suggestions? Maybe I'll download them!