Cred said:
pm on how to get it please, I dont want to download a virus.
The official download for Cain&Abel is
here but its a windows program, so I don't know how you'd go about getting it on mobile. You could get a friend with a laptop to bring it in, and connect one of the schools ethernet cables to the laptop then use Cain to get the password. You could also take accounts from people that have signed in on the school login if you're an ass. Good luck!
If your school has wireless computers this is way easier. Just open the wifi menu, right click the wifi you're connected to and click 'Properties' then 'Show Password'. No idea how to do this with ethernet connection though.