Batuhan Bozkurt’s Otomata is a generative sound sequencer for iOS.
On one level, Otomata is a music toy – just press the buttons and something musically interesting emerges. Otomata is also surprisingly deep, though, because it uses cellular automaton style logic:
Each alive cell has 4 states: Up, right, down, left. at each cycle, the cells move themselves in the direction of their internal states. If any cell encounters a wall, it triggers a pitched sound whose frequency is determined by the xy position of collision, and the cell reverses its direction. If a cell encounters another cell on its way, it turns itself clockwise.
This set of rules produces chaotic results in some settings, therefore you can end up with never repeating, gradually evolving sequences. Go add some cells, change their orientation by clicking on them, and press play, experiment, have fun.