System Tray App
There is a short initial setup: Start the app (This takes a while 15s). A music note icon will appear in the system tray and a window will open prompting you to select your service (Spotify or Last.fm) and enter your API keys (see section below) Press 'Save' and start the app again.
Introducing HostSwitcher: A Tray App for Some of You My tray application, HostSwitcher, lets you re-route entries in your hosts file with a single click on the context menu attached to the icon in the system tray. I needed this myself because my work involved a network application that communicated with several servers at any given time. Axigen Outlook Connector is able to show notification messages through informational balloons regarding its activity (such as server connection status changes, synchronization statuses, quota information or password expiration warnings), via a System Tray application. Installing the System Tray application. The Axigen Outlook Connector System. Windows 10 has a built in notification system to let you know when an app is accessing your location. This notification does not show up in the Action Center but instead in the system tray. Travis is asking how to control the system tray and not Lynx through GPO. In GP you can set it to force hiding icons in the system tray or showing them, but there is no option to selectively choose like there is in Windows Vista/7. So the question is, how does he selectively choose. I also was wondering the same thing.
Lync is not managed via GPO, it has its own management console and pulls its settings down from its own server. There is a GPO ADM that should be on the client install media for Lync. I believe this GPO only has settings for where to find the Lync server, similar to how the WSUS GPOs work.
System Tray Application
If it is possible to set this, it is likely through Lyncs own console. If you can find the registry key that sets this, I can write you a little custom ADM to set it.
System Icon Tray
Edit: After further research, the Lync ADM only contains Bootstrap Policies. An online copy can be found here