the topic about #Matrix / #Matrixchat touched upon how "Matrix isn't available on cellphones", and I searched and found stuff...this stuff:
I Googled for:
element play store
and Google found this immediately: https://play.google.com/store/apps/details?id=im.vector.app
https://googlethatforyou.com?q=element%20play%20store
unless you got an iPhone ofc, that app should work...I assume.