[ajstiles]

I've recommended a "web app first" approach to some of my clients.

You might find parse.com services cover your user and notifications requirements, and perhaps even your REST backend.

[victor9000]

thanks, the web app approach certainly makes a lot of sense. my only concern is whether html5 can get access to the phone's resources like the camera, dialer, etc.

[rahimnathwani]

Cordova will provide access to the camera:

http://cordova.apache.org/docs/en/2.5.0/cordova_camera_camer...

And maybe the dialer:

https://github.com/gibsosmart/cordova-phone-dialer