Ben_hawk asked how to do this on Stackoverflow, and I was both curious how to do it myself. Turns out it’s not too tricky – see my answer in the same post.
A big reason for doing this even early in development, prior to distributing builds to anyone else, is that it makes it much more obvious which build you’re working on. My release icon is a 3D rendering, for example, while the build one is the wireframe. Same geometry, so the icons form a distinctive pair, but different enough in colour and style that I can see at a glance if I’m accidentally running my stripped release build in lldb, or my unoptimised debug version in Instruments.
