Some great apps I've found to have are as followed:
Aurora Feint-So much content, a puzzle game
BreakClassic-I got it for free, Addicting, should add the feature to put in 3rd party levels
Cube runner-Really a great app, sounds dumb, but really addicting
CubicMan-I have the lite version, still a good game
Enigmo-Really great now that you can download custom/3rd party level packs
iProcrastinate-The most useful app I have
KuGon-I got the lite version, beat it(only has 6 levels) and then bought the full version, really quite a great game
Sportacular-Best Sports app I've seen, updates every 30 seconds, just check it out
Sudoku Classic-A sudoku app, thats free
Tap Tap Revenge-Addicting, fun, like guitar hero/rock band
WeatherBug-Great app shows warnings, radar, cameras of your area, an extended weather app
Vector Pong-Hard game at first, then once you get used to the controls it gets easier, addicting
Aurora Feint-So much content, a puzzle game
BreakClassic-I got it for free, Addicting, should add the feature to put in 3rd party levels
Cube runner-Really a great app, sounds dumb, but really addicting
CubicMan-I have the lite version, still a good game
Enigmo-Really great now that you can download custom/3rd party level packs
iProcrastinate-The most useful app I have
KuGon-I got the lite version, beat it(only has 6 levels) and then bought the full version, really quite a great game
Sportacular-Best Sports app I've seen, updates every 30 seconds, just check it out
Sudoku Classic-A sudoku app, thats free
Tap Tap Revenge-Addicting, fun, like guitar hero/rock band
WeatherBug-Great app shows warnings, radar, cameras of your area, an extended weather app
Vector Pong-Hard game at first, then once you get used to the controls it gets easier, addicting