A NowPlayingSessionManager wrapper library - used for controlling SMTC apps (e.g. Groove Music, Movies & TV, etc...)
MIT License
Provides access to playback sessions throughout the system that have integrated with SystemMediaTransportControls to provide playback info and allow remote control. For example it allows controlling the playback of Groove Music remotely.
GlobalSystemMediaTransportControlsSessionManager is a WinRT API, available since 17763 (Windows 10 RS5 - version 1809). GSMTC is a wrapper around NPSM.
Windows 10 1511 (10586) or newer
Make sure you have proper capability set in your app manifest, which is required since 17763, otherwise you'll get an access denied exception.
<uap7:Capability Name="globalMediaControl" />