VRChat

TrackStrap™ compatible and Vive Tracker features: 

We support a single tracker for hips, or three trackers for hips and feet, allowing a full range of body motion including sitting down, crossing legs, laying down, kicking and dancing! (note: This feature is still in development) 

From the Steam Page: 

Join our growing community as you explore, play, and help craft the future of social VR. Create worlds and custom avatars. Welcome to VRChat.

Check out the Steam Page