This experiment won't really work on mobile, as it needs a keyboard.
This demonstrates multiple oscillators and an ADSR envelope. The attack and release can be adjusted on the fly with no weird artifacts. There should be no clicking, the performance is high enough to cope easily.
click anywhere to enable sound, then press keys to play notes. The keys of the bottom keyboard row on a qwerty keyboard are the white notes, where "z" is C, "x" is D and so on, up to "," which is C again. Letters "s", "d", "g", "h", and "j" are black notes.