VRChat - Create and play in virtual worlds with others
Next! Fitness - A.I. powered gym
Vircadia - Vircadia is an open-source and decentralized real-time VR creation platform for university, enterprise, social, and OpenSim users.
Dualnback.works - Dual N-back is a specific brain training exercise, that's been shown by research - it might improve fluid intelligence.
XSight - Find friends and places in AR using your phone camera
PopcornTime iOS App - Watch movies & TV shows instantly on iOS (no jailbreak req.)