What are we looking at:

This is a proof-of-concept for desktop–smartphone interactions. Each QR code can be scanned with a smartphone, and a connection between the open page and the smartphone will be established.

Gamepad RTC turns the smartphone into a simple game console pad, with a thumbstick and A/B buttons. Data is transmitted to desktop browser using WebRTC p2p.

Motion uses the phone's orientation to move a ball along a track. Uses WebSockets.

Fish uses the phone's orientation to detect direction and fish-like wiggling movement to control a fish in 3D space. Uses WebSockets.

I think these POCs show that smartphones could be used to design games and other interesting interactions between devices, with very little set-up overhead.