I struggle to understand difference between mvvm fresh & mvvm light, Or I can say I am just jumping into it. So anybody just shed a light on it to be comfort to use it with xamarin.forms application.
I have used FreshMVVM in couple of mobile apps for both Small and Tablet devices. FreshMvvm is very light yet still gives you all the features you need and it is specifically designed to work on Xamarin Forms. It adds extra parts to existing Xamarin Forms capabilities like :
They have a very nice reference and detailed information in their project site. https://github.com/rid00z/FreshMvvm
Update : What about MvvmLight?
All of these frameworks provides common features. Because the goal of all of them is same - providing cross platform tools that would support all of the above features I listed for FreshMvvm. The only differences however may be some of them might have some more features included and the way of implementing their Base Classes.
Recommendation for you : You should learn FreshMvvm (more light and easy to learn) and MvvmCross. These 2 are the current popular ones for Xamarin and Xamarin Forms platform.