Comment by daghamm
Even iOS exist in many different sizes and configurations these days. If you look closer at the pictures in that post you will see multiple iphones.
I think it is fair to say that no serious developer will publish an app without testing on at least 2-3 physical devices.
True, but iOS doesn't have OEMs having their own forks, which takes this to the same level as J2ME used to be.
Whatever they come up in GUI features, changes to AOSP behaviours, custom drivers, their own extended SDKs on top, hardware form factors,...