There's actually a surprising number of CLI implementations of popular protocols out there. I recently started using Hangups (https://github.com/tdryer/hangups) for Hangouts. And there's one for Play Music too although I can't recall its name at the moment.

Only thing I'm really, really missing now is a CLI for KeePass, but I'm considering writing one myself in Go, since I've been looking for something to do for practice in Go anyway.