`_service.Devices` is hooked up to a `ConnectedDevicesChanged` event, and updates with a full list of connected devices. Need to display all connected devices on the UI. (ideally not completely clearing collection, just adding/removing newly connected/disconnected devices, but i'm not doing that at the moment)

form.xaml

<ListView ItemsSource="{Binding Devices}" />

ViewModel.cs

public class MainViewModel : Screen
{
    private ConnectionService _service;
    public ObservableCollection<DeviceViewModel> Devices { get; private set; }

    public MainViewModel()
    {
        Devices = new ObservableCollection<DeviceViewModel>();
    }

    protected override void OnActivate()
    {
        base.OnActivate();
        _service = ConnectionService.Start();
        _service
            .Devices  // :: IObservable<IEnumerable<Device>>
            .Select(ds => ds.Select(d => new DeviceViewModel(_service, d)))
            .LinkTo(Devices); // syncs observable collection every time connected Devices updates
    }
}

public static class Extensions
{
    public static IDisposable LinkTo<T>(this IObservable<IEnumerable<T>> source, ObservableCollection<T> target)
    {
        return source
            .ObserveOnDispatcher()
            .Subscribe(items => 
            {
                target.Clear();
                foreach (var item in items)
                {
                    target.Add(item);
                }
            });
    }
}