Xamarin Forms lets you build native apps using a . NET cross-platform technologies that target the mobile, tablet, and desktop form factors on Android, iOS, Windows and more.
This is the source code of the videos where you will learn how to build a COMPLETE cross-platform Android & iOS Weather Application using C# and Xamarin.Forms.
You can watch the videos here: https://www.youtube.com/playlist?list=PLsVdRN_cc4gveR7EOH5WZHQK1Jt75TOK7