How do YOU handle versions & app-comments in your apps?

[_Mac]

Since I know there are many experienced Xcode developers here, I thought this was the best place to post this question.

Just wonder which is the best practice to handle different versions of my apps and also how to keep notes / version (app history comments).

Example:
App X version 1.0.0 is done and want to save it "as is" including all resources, so I can return to it. I also want to be able to move on with the app and experiment with new things for version 1.0.1. And of course post updated versions of App X to App Store along the way while keeping a complete history.

Solution?
Is Xcodes "Snapshots" the way to go? You can add comments / snapshot (ie versions?). Have read somewere that Xcode has some built-in version-handling, but I have not found it.

Any tips or pointers how I can handle this? Thanks!