My software develpoment background for the past 25 years has been fixed in OOP. Initially C++, then Java and then C#. About 6 years ago I started developing apps for the iPhone and iPad using Objective C, and I have to say my opinion of Objective C was not very complimentary. I found the syntax obscure and its OO credentials less than stellar. I was even less impressed with Swift, which I thought dumbed down the development at the expence of making the apps more error prone.
I was aware of XAMARIN and the fact that this would provide a C# development env, but at the time the cost of a licence was beyond my budget, so I persevered with Objective C.
Imagine my delight when Microsoft bought out MONO and released XAMARIN for free. This section is about using XAMARIN and devloping Apps for the iPad and iPhone.