This application lets you see the world in a way you never experienced before! By combining video from two nearby iPhones or iPads the stereo base is increased by the factor of 10, 100 or even 1000, increasing your effective stereoscopic range by the same factor. This means that we can perceive depth when looking at very distant objects, like clouds or mountains. This is how the hypothetical giant would see the world (because obviously, giants have wider eye separation than humans).
The idea comes from the xkcd web comic by Randall Munroe#941 "Depth Perception". As depicted in the original, the setup consists of 2 stationary webcams, and the third display device. Today our phones are our webcams so there are just 2 devices - one for the left and right eye. There are no remote servers, websites to visit, user accounts to create, because the application does not transmit the images through the internet, only locally between devices. The drawback is limited range, the advantage is that we are not dependent on the infrastructure.
How to use this app?
Simply click the Connect button and select another nearby device. Point both cameras at the same distant object and choose the desired display mode: red-cyan glasses or Google Cardboard VR headset.