Please fix the in-app purchasing documentation.
- It contains broken links which are supposed to go to sample code.
- Links to specific detailed explanations that just go back to the main iOS Documentation Index page.
- Sample code (when you manage to find it) which contains stuff which was deprecated back in iOS 5.0
There is little authoritative information on certain aspects of Xamarin development available (only one book, which came out a few weeks ago and as yet appears to be unreviewed anywhere) which makes the onsite docs all the more important.