Wiisp - Simple drone synth. 2 Osc with fm, delay with fm. Made with puredata.Oscillators are sine waves with adjustable pitch. The second oscillator has a higher pitch limit. Both are directed to a delay, with optional fm from oscillator A. Glide creates a smooth transition between changing any of the values. Higher glide, longer transition.
https://play.google.com/store/apps/details?id=com.thiiird.deej.twoo