GridView1: Simple add and insert items into GridView control
GridView2: Display persons in groups using initially sorted Collections of Collections
GridView2: BottomAppBar with button to add new person and simple groups re-sorting (lots of flickering)
GridView2: Use ObservableCollection and INotifyPerson.PropertyChanged for less flickering, keep groups and persons sorted using IComparable and AddSorted extension method
GridView3: Manual switching between GridViev and ListView controls
GridView4: Switch beetween visual states using VisualStateManager and storyboards