Shameless plug here.. I've been working on a service that kinda solves a similar problem, called Postways [1]. Even though Postways also provides a unified API

Shameless plug here.. I've been working on a service that kinda solves a similar problem, called Postways [1]. Even though Postways also provides a unified API for sending email, SMS and mobile push, the main focus of Postways is actually on managing the message templates. When you work with a team where not everyone is a developer, updating the actual message text can be a major problem, especially when the message text is in source code or various different places. [1] https://www.postways.com https://www.postways.com