This script will influence your Xcode project’s version number every time you build the project. It bases the version string on a combination of your git repository’s tags and the current git SHA1.
For instance, if you build the project without any tags (say, a beta version, or really early during development):
If you then finish your first release and tag it as version one, you’ll get something like this when you build it:
If you build your project in between releases, you’ll get all the relevant information together:
Finally, if you’re working on a development branch of some sort, that info will be displayed as well: