Fallout shelter not compatible?

[Edit] got it working on the device. Still doesn't explain why an older device is able to get the app from store..

So my Galaxy nexus is not supported google says.
Minimum SDK is 4.1 for the app.

OK, so to bad right? Well..... Then there is this..


How?
What makes the Nexus S be supported but Galaxy nexus not?(dont own the nexus S any more)
And is there any way to get it on my Gnex? I do have other devices to pull the apk form, but it gives me an error that i didnt buy the app.