social music-making applications for iOS, Android,: smule and ChucK

smule is a society and also an app.
https://en.wikipedia.org/wiki/Smule

smule

Put a recording studio in your pocket.
Sing your favorite hits with others.
Android and iOS
https://www.smule.com/

Sing! Karaoke

https://en.wikipedia.org/wiki/Sing!_Karaoke

Ge wang 

 known for inventing the ChucK audio programming language
https://en.wikipedia.org/wiki/Ge_Wang