It's all very well checking layouts in Interface Builder but until the app is actually running it's hard to tell whether everything is in the right place. Peek allows you to toggle your debug build into a UI inspection mode where you can see some summary information. Then if you need more detail, double tapping will open up detailed properties for the view.
I talked about package collections in the Swift Package Index when they appeared in the first beta of Xcode 13 and Swift 5.5. However, I didn't explain how to create your own back then, which is where this article from Shaps Benkau comes in.
It's interesting to note that the article also covers signing package collections using the brand new "Swift Package Collection Certificate" that you're now able to create in your developer account.