I would like to write a custom control which will look like [this](https://github.com/nicklockwood/CountryPicker) one using Xamarin.Forms. I know that when we want to modify the existing control from Xamarin.Forms we are using [Custom Renderers](https://developer.xamarin.com/guides/xamarin-forms/custom-renderer/), but this control is something more than `Entry` and the solution is not obvious to me.

My question is how do I start working on this task? What control should I extend if I would like to use custom renderer? Is there some other more effective way to achieve this?