I have tried the app on Android 2.3, 4.4 and 5.0. The latter version is the only case where it's not stuck on the loading screen (i.e. it actually launches). The timer is however broken, making it not functioning. I have really tried, more than I'd like to admit, and I've generated 0.7 MCZ over 17 days.

I agree you shouldn't get rich or see it as payment, but if you want people to use the app you'll need to provide an incentive. Doing a referral campaign now,with a non functional app is clearly not a good idea.