With Google now claiming an 80%+ worldwide marketshare percentage and Apple maintaining a 60%+ share of mobile profits it is no longer an option to support one or the other; good mobile apps support both platforms and leverage those platforms unique idioms appropriately. But even with the code sharing abilities offered by Xamarin we still end up doing a lot of work with UIs. For this, Xamarin has created Xamarin.Forms, a unique tool that allows developers to create a single UI definition that gets interpreted for each supported platform. This enables developers to quickly write applications in as many as 4 platforms simultaneously. In this talk, I will showcase how this works including a full discussion of custom renders and styles, and where Forms makes sense and where it does not. I will also cover FreshMVVM which is fast becoming a favorite among developers looking to leverage MVVM in their Forms applications.