Are you sure you have it set up as a mobile app, and that you’re using the correct tracking ID? Also, are you telling it to track anything, such as:
analytics.trackView('Screen Title')
I’ve noticed that that plugin will only track analytics if the app is built, so it shouldn’t report any desktop statistics. It also won’t show real time data for about a day after you’ve created the tracking number.
If you still don’t have it working, maybe this topic will help: