Have you ever wanted to share your screen across two devices? The uses for this are endless including demonstrations, games or just for fun. Swip.js can help.
As of the writing of this post, the product is in very early release, but the uses are almost endless.
All you need to do is put two (or more) devices side by side and pinch the edges together. And it's not just limited to a single platform. You can see from the demo that it works on IPhone and Android devices and even different sized devices.
It will be interesting to see where this product goes in the future.