[ntaso]

Unless, of course, there's no backend and your app is a full-blown tool to run on the device only.

[falcolas]

You can still have 95% common code with shims to fit the different platforms. Oddly enough, the original Doom is one of the best examples of this process in action. It supports Windows, Linux, and a host of other OS targets, at a time the interfaces couldn't have been more different.