Canny - Canny helps you collect and organize feature requests to better understand customer needs and prioritize your roadmap.
Serum - VST for FL Studio, Ableton Live, and many other VST supported DAWs. Heavily utilized in EDM.
hummingbot - Automate crypto trading with your own market making bot
Surge XT - Open-source subtractive-hybrid synthesizer formerly sold commercially as Vember Audio Surge.
Period Tracker - Period Tracker, the easiest way to track your periods!
Omnisphere - Piano, pad and synth VST for DAW's.