Are the 4 Android buttons standard? Ex. back button, menu button

Question

Are the physical buttons that Android phones come with standard? Specifically the back, menu, home, and search button? In my applications I assume everyone has a back button

Answer 1

Amazon Fire phone do not have a back key.

On Android platform it is generally wrong to assume that, standard defined by an entity will work everywhere. It is usually depend on device manufacturer.

if your app rely on some specific device feature, make sure that you check and recheck, if that specific feature exist on device. Some time just putting information on AndroidManifest is not enough.