Why is Android app not compatible My son's got a Kurio 7 tablet. I've installed the Amazon App Store on it and noticed not all apps are compatible. Bad Piggies for example won't install. The Amazon App Store says its not compatible with his device. Why is that? Bad Piggies is supposed to support Android 2.2 and the Kurio 7 has Android 4. Other than that it doesn't say anything about the requirements. What other things can make an Android device incompatible with some apps?
There are a few different things on Android that specify whether or not an app is compatible with a device:


The author can specify minimum and maximum supported versions.  Meaning that even though 2.2 is supported, 4.0 may not be.  (Probably not this in your case). Reference
Apps may require certain features to be available, another thing that the author puts in the manifest.  This specifies things like needing a camera, needing an accelerometer, needing internet access, etc.  If your device doesn't have one of the features, it may show as not compatible. Reference1 Reference2


Here is a list of possible features that may be required by the app's developer.



As an example for #2:


  When you declare "android:required="true" for a feature, you are specifying that the application cannot function, or is not designed to function, when the specified feature is not present on the device.