Proxy phone number via Twilio or Google Voice for the times when you'd rather not give your real number out.
Audio translations for digital books using espeak + pdftotext + shell scripting. If you didn't know, espeak can output wav files. It's a nice way to read since my commute is 3 hours a day.
Recipe management for putting meals into rotation and generating a shopping list. Check out Gourmet or Krecipes on linux. It could probably be hooked into a grocery delivery service like Prime Pantry or just migrated to one.
General automation with Twilio + serverless cloud functions is pretty good. There's a new Twilio tool for building IVRs (interactive voice response trees, like those phone menus you get when calling a cable company). The super cheap on-demand pricing for cloud functions makes this basically free to run.
I started a personal SMS/Voice service for some of my tasks like what's on [favorite radio station], Bus line directions, shops near me, etc. There's no real point yet but I feel like it could have uses that are actually helpful...