Majic Jungle Software has Chopper (iTunes Link) for the iPad in the iTunes App Store for FREE (regularly $2.99) for a limited time.

Chopper is an action packed side-scrolling helicopter game. One of the great App Store classics. Complete your mission and return to base, while avoiding enemy fire from tanks and bazooka wielding mad men in this action packed side-scrolling helicopter game. Chopper is a universal app. You only need to purchase it once and it will run both on iPhone and HD on iPad at no extra cost. Play through twenty levels in each of four difficulties. Tilt to fly, and touch the screen to drop bombs or fire your machine gun.