NOVEMBER 18, 2014 UPDATE: NVIDIA will continue to run our old GRID Beta app for a few more months to give you time to finish your current games. We recommend all users switch to the new GRID Gaming Service which is now integrated into the SHIELD Portable Hub, expands the service regions, and includes more games.
Yes, you can switch away from the GRID app while a game is running and resume your game as long as you switch back to the GRID app within five minutes.