Hi,
Unfortunately, there is currently no native jammr app for ChromeOS.
It should be possible to run the Linux version of jammr on Chromebooks, but this involves a number of steps. If you want to try it here are some pointers:
If you have an x86 Chromebook it should be possible to run the jammr app for Ubuntu LInux under crostini. crostini is a ChromeOS feature that allows you to run Linux apps on your Chromebook. Setting up crostini requires some familiarity with Linux:
https://chromeos.dev/en/linuxhttps://www.reddit.com/r/Crostini/wiki/howto/run-ubuntuIf you have an ARM Chromebook the same should be possible but the jammr client needs to be compiled from source, which requires knowledge of how to compile programs on Linux. The jammr client is open source and available here:
https://github.com/wahjam/wahjam/