bullet-ane is a native extension for the Bullet physics simulation library. It has true native implementations built for iOS (7.0 SDK), iOS Simulator and Android. All other platforms fall back on AwayPhysics, a pure-AS3 implementation of Bullet, meaning the extension will work on all platforms AIR supports. Compared with AwayPhysics, bullet-ane increases performance on mobile apps by an order of magnitude. There is a comparison video available.

The extension is currently written to work with Away3D, but certainly could be made compatible with other Stage3D-based AS3 graphics libraries.

Sample

var _view : View3D = new View3D();
this.addChild(_view);			

// init the physics world
var _physicsWorld : DiscreteDynamicsWorld = new DiscreteDynamicsWorld();

// create ground mesh
var material : ColorMaterial = new ColorMaterial(0x252525);
var mesh:Mesh=new Mesh(new PlaneGeometry(50000*scale, 50000*scale),material);
mesh.mouseEnabled = true;
mesh.addEventListener(MouseEvent3D.MOUSE_UP, onMouseUp);
_view.scene.addChild(mesh);

// create ground shape and rigidbody
var groundShape : StaticPlaneShape = new StaticPlaneShape(new Vector3D(0, 1, 0), 0);
var groundRigidbody : RigidBody = new RigidBody(groundShape, mesh, 0);
_physicsWorld.addRigidBody(groundRigidbody);