I don't buy this at all. In another thread, Rick Strahl posted about the problems of getting this type of app into the Apple store. In addition, if you're running on a mobile device, users want the application to look like a native app on the device. That is very different between iOS, Android, and Windows.

If you're going with a 100% web app, I advise not going with something niche like you're promoting. It's harder to hire people for it. It's harder to find web support resources. And finally, it's harder to sell into companies that want to self-host because they know nothing about it.

>You end with a single, 100% web-based application that the user can run on any device, any OS, anywhere, without writing a single line of HTML.