SYXcodeIconConversion is an open source Xcode plugin from dvkch that overlays the version number, and tag for beta versions on the Xcode icon.
This is a great addition to Xcode for anyone running multiple versions (especially if you run more than one at the same time).
This image from the readme shows different versions of Xcode running:
You can find SYXIconCodeConversion on Github here.
A nice Xcode plugin for those who like to utilize beta versions of Xcode.
See more: Xcode plugins.