Quite often I need to kick off a long-running process for a client, then resume work immediately once it's done. pg_restore, pg_basebackup, pg_upgrade, and vacuumdb --analyze-only all come to mind as examples. The ideal thing is to get a text message upon completion. When I'm working on my own boxes, I can just mail(1) my mobile carrier's text gateway, but I can't count on clients' servers having sendmail or the like set up (they usually don't).
Enter TextBelt. This service is a dead-simple HTTP-to-SMS gateway. Adapted from their docs:
curl -X POST https://textbelt.com/text \ --data-urlencode phone="$MY_MOBILE_NUMBER" \ --data-urlencode message='The process completed.' \ -d key="$MY_TEXTBELT_API_KEY"
Cleartext HTTP is also supported, in case the client box has broken SSL libraries. My texts are always nondescript, so I don't mind sending them in the clear.
The whole thing is open-source, so you can set up your own TextBelt server. Or you can be lazy and throw a few dollars their way for a certain number of texts. I rather like this business model, actually, as a way to support open-source work.