For context, here is a list of similar services:
- https://www.burnerapp.com/
- https://www.line2.com/
- https://hushed.com/
- Google Voice
- http://www.coverme.ws/en/index.html (it's not..super clear if this is a chat protocol with some sort of weird SMS glue or if it's a genuine bridge)
- https://www.sideline.com/