Could I ask what features you've found that don't work? Not so that I can help, unfortunately, but because I'd like to be tipped off to problems I might meet!
The web viewer does not work in the IWP client when IE is used as the browser (at least IE8 or IE9). The same code works great in Chrome. I checked with the FMP support folks and they verified this as a known issue.
Basically, I'm creating a report in HTML and storing it in a global field then displaying the HTML in a web viewer. Works great in the desktop and iOS client, just not IE.