Though its developers recently announced that it’s no longer under active maintenance, it’s worth at least mentioning Caliburn Micro in here. This is a pretty small framework originally designed to build apps across XAML platforms. Though its applications narrowed throughout the years, its strong support for MV patterns provided its users with enough quality and testability to easily build apps.
A small, yet powerful framework, designed for building applications across all XAML platforms (.NET 4.5+ and .NET Core 3.0+). Its strong support for MV* patterns will enable you to build your solution quickly, without the need to sacrifice code quality or testability.