[Jacob]

You actually got iP 4 with iiOS 5.1 jailbroken? I didn't think it was out yet. I ave a 3GS with iOS 5.01 jailbroken. Not much difference really.


But here is a short list and what they do
Cydia - the obvious app needed
Installous - free app store aps
SBSetting - adds a lot of quick access functionality to your device by swiping the status bar
Activator - Ad shortcuts to apps, etc.



sources:

xsellize
hackulous
modmyi

those are the best.