Minimoog Model D app 

https://apps.apple.com/us/app/minimoog-model-d-synthesizer/id1339418001

Another storied name in electronic music, Moog -- maker of the eponymous synthesizer -- is offering its Minimoog Model D app for free. The app, which cost $5 before the coronavirus pandemic took hold, is based on the company's 1970s-era Model D synthesizer, which has been a favorite of musicians ranging from Herbie Hancock to Dr. Dre.  

Featuring more than 160 preset sounds, the Minimoog Model D app is simple enough to use; you'll have fun just playing around with all of the sounds, dials and buttons. But there are also sophisticated features to help you filter and control your bleeps and boops, make loops and beats, share your productions -- and even integrate with other MIDI devices. According to a company representative, the Minimoog App will not remain free forever but there is no set end date.