I have used a lot of twitter apps (too many) but i was curious which one you guys liked and why? What features makes you use that app over any other? Also, while we are talking about twitter apps, do any apps allow you to set up notifications when certain people tweet? For example, the official Facebook app sends you a notification anytime one of your "top group" members posts a new status. Anything like this for twitters plethora of app options?