Noty is a simple note app.
It is not at all well designed, but it has every functionality to demonstrate how to use iCloud. How to create, delete, (though no rename function), conflict resolution, etc.
It is created based on a wonderful tutorial on raywenderlich.com:
The original tutorial was written a few years ago, so some minor adjustment was made. I hope beginners of iCloud programming can use this as a starting point and create some awesome stuff.
Here is the link of it on GitHub: