Currently I’m in the process of building a mobile PoS app for iOS. For this I integrated a software barcode scanner. As it is not to hard in Swift and plenty examples are available, I felt the examples I looked at all missed something or looked very alike. Additionally, I like to create minimal implementations for the sake of really understanding the principles at work.
So, I built a complete demo with a basic scanner and pushed it to GitHub, check it out if you are interested.