I think Sandstorm is great for healthcare! I think there's a bunch of compliance needs that you can meet with a Sandstorm server which might otherwise need multiple external tools. And for a smaller office, Sandstorm being easy to host on a single small box (I use a NUC personally) is pretty handy.
I would say Sandstorm's own web UI is not well-optimized on mobile. Many apps work fine via mobile browsers, but it isn't the best experience. But as long as you can connect a mobile application to an HTTP API, it would work very well as a backend. TinyTinyRSS is a great example: The Sandstorm app itself doesn't work well on mobile browsers, but there are dozens of great TTRSS apps that work great, and can connect to the Sandstorm app.