One of the best ways to learn something is to do it, so I've done a little Xamarin Forms development to get a feel for what it can do. I've created a small game called Simonish and taken it all the way through to the Google Play Store for Android. Whilst Xamarin Forms can also target IOS apps I'm not an Apple guy so I'll leave the Apple App Store for another time. The source code is on GitHub if you want to take a look.
The game looks a bit like the classic electronic game Simon (originally launched by Milton Bradley in 1978) but is a lot easier to play, just requiring quick responses rather than a good memory.