i supplies basic memory robbing and process hogging you dont need av on an android device.
titanium back up is a good choice and we have clock work on these things so you can just make a nand backup
Task managers and av programs are worthless i have been running android devices for over two years and i own 3 tablets and i have never had a virus i just think its a hog on an already slower system
you dont run a task manager or anti virus on your linux based system do you I dont.
not trying to be critical just trying to save you some mem.