PS - don’t discount Monome, it has a very different flavor than Zynthian and is in many ways more of a musical instrument. It’s definitely worth investigation if you’re a synth nerd.

There are plenty, but CDM is my favourite:

https://cdm.link/

See also, matrixsynth:

https://www.matrixsynth.com/

They both often have the same content, but CDM has a nicer vibe that I feel more comfortable suggesting ..