Blocking specific applications from accessing the network while not active or on screen

Question

Is there any applications out there that can let me selective limit network access when i put a program into the background?

Answer 1

Hmm, difficult problem
Your only bet is rooting; and app like droidwall which is front end for iptables. And then you would have to add rule that states block any app that is running in background. That I'm not sure how to achieve.