I used to use Pidgin with OTR[0] for e2e encrypted chat over google & facebook. It was pretty fantastic, messages were inaccessible to facebook and google even with a court order so I didn't need to trust them.
Also used Finch for a bit[1]. For a time I had a pretty great setup on a local VM (running the PHP app I was working on): one tmux tab with work, another with a pane for finch (for chatting on FB & google), a pane for IRC, and a third pane for ttytter[2], the amazing twitter CLI. If someone nontechnical walked by they'd see a terminal and it looked exactly like I was working, not chatting on IRC & facebook, and looking at twitter :D
0: https://otr.cypherpunks.ca/ 1: https://www.systutorials.com/docs/linux/man/1-finch/ 2: https://www.floodgap.com/software/ttytter/