Blob Opera

https://artsandculture.google.com/experiment/blob-opera/AAHWrq360NcGbw?hl=en&cp=e30.

Viola the Bird

https://artsandculture.google.com/experiment/nAEJVwNkp-FnrQ

Creatibility at Google - Several Sound making apps:

https://experiments.withgoogle.com/collection/creatability

More Sound experiments at Google:

https://experiments.withgoogle.com/search?q=Sound+and+Music

Chrome Music Lab:

https://musiclab.chromeexperiments.com/Experiments

Hookpad:

https://hookpad.hooktheory.com/

Muted.IO List of Music Apps: