Online Community of Zenith Builders and Flyers
Avare. It's most of what anyone needs, works fine on a Tab, and is free. Takes a while to learn but then you have it...
Flight Pro is a nice android app. Not sure of your definition of cheap though, it's $6.99 for the data subscription. Its a pretty fully featured app though and seems to run well on my Samsung Galaxy Note and a tablet I have.
The website is: www.flightpro.com