Yes, and yes. https://play.google.com/store/apps/details?id=com.gyagapen.cleverconnectivity https://play.google.com/store/apps/details?id=com.gyagapen.c... It

Yes, and yes. https://play.google.com/store/apps/details?id=com.gyagapen.cleverconnectivity https://play.google.com/store/apps/details?id=com.gyagapen.c... It essentially disconnects data when screen is off (the algorithm is a bit more complex, but that's the basic idea). Especially in areas where my phone passes between 2G/3G/noSignal often, I see much improved battery life.