Words with Friends! I've actually been playing for awhile, but now that my husband has given me his old Ipod Touch, I am now even more addicted. It's just way too convenient to play every time I get a little reminder that dings and pops up on the screen. I just think of it as enhancing my vocabulary. :) I tell you...some of the games turn downright brutal. Sometimes I get the best letters and get super lucky with placement, and then the next game I get all vowels and have nowhere to put them.
Do you play Words with Friends? What's your favorite app? -- I'm always looking for new ones! They don't have to be games either, just ones you think are convenient or really like.