list of few online apps that my daughter likes:
- https://tahti.studio/ – decent groovebox
- https://citizen-dj.labs.loc.gov/ – simple groove box / beat maker based on public domain samples
- https://musiclab.chromeexperiments.com/
- https://www.vitling.xyz/toys/acid-banger/ – endless acid banger
- https://roland50.studio/ – roland’s TB303, TR808 and few other synths/drum machines
longer lists of tools: