Starting in 2011, OnStar will begin offering a smartphone application at no extra cost as part of their basic subscription plan for all GM brands. Smartphone users will be able to use many of OnStar’s features right from their phone. Some of those features include the ability to remotely start their vehicle, activate horn and lights, and lock/unlock their vehicle’s doors from their phones. They will also be able to check vehicle information such as: fuel tank level and range, remaining oil life, current and recommended tire pressure and lifetime average miles-per-gallon. Watch a demo video after the jump.