The Grid is a musical instrument which uses images from the device’s camera. Given this, the browser must be allowed access to its interface. Turn the sound on and wave you hand before the camera.
In the grid of 5 x 5 cells, the rows correspond to octaves (the lowermost row is the first octave – “bass notes”). The columns contain the successive sounds of the C major pentatonic scale: C, D, E, G, A, starting from the left-hand column. The cells located in the same columns have the same sounds ascribed to them, but in consecutive octaves.