X-Plane 9, one of the most impressive flight sims, is now FREE on Android (it used to cost $20!)
X-Plane is one of the sims where it actually calculate the aerodynamic forces of the air against the wings and such, so it is extremely realistic. The free version requires a huge download for the terrain data, but after you're done, and if you have a decent phone, you'll get a spectacular game where the terrain is so realistic you'll swear it's on a PC.
And this is a full flight-sim, complete with NAV beacons, throttle, flap, rudder, brakes, and so on. You can also set up "missions", watch instrument panels, and more.
Definitely give it a try.