Instant technical compatibility, definitely, but a 20% reduction in physical size on everything has some potentially nasty usability implications. A 44px-high button that is 0.333" high on an iPad is 0.27" high on an iPad Mini, for example.
iOS apps are laid out in pixels, while Android apps are laid out with physical units (in, mm) or density-independent pixels, which means that a screen size change doesn't necessarily mean a usability change on Android. Two totally different layout mechanisms, and while this means that Android apps are less precise in their layouts, I'll argue that it improves usability across a range of devices.
iOS apps are laid out in pixels, while Android apps are laid out with physical units (in, mm) or density-independent pixels, which means that a screen size change doesn't necessarily mean a usability change on Android. Two totally different layout mechanisms, and while this means that Android apps are less precise in their layouts, I'll argue that it improves usability across a range of devices.