Motorola Droid

its called Advanced Task Killer and u can get from marketplace or whatever googles app store is called.

there is no task manager on the device to close apps so alot of issues like slowness or freezing can be remedied, even battery life can be extended if u keep the number of running apps to a minimum.

also keep in mind pressing hold down the home key shows most recent used apps, it doesnt show what apps are currently running.