Ordinarily on any other unix you would open up a terminal and type ps aux to see a list of all processes running. On a Mac you can go to activity monitor and see a similar list. I imagine on a jailbroken iOS device you could also ssh in and type ps aux. Amusing enough, Apple has provided a way for developers to view what process is running on their phone. While the iOS device is plugged in, in the instruments app that comes with Xcode, create a new profiler with any one of the options. Then select your device from the top to have it show every single process running on iOS. Nifty.