Interacting with Apps
You can terminate apps which are running in the foreground and the Recent at any time. To close an app, hover over the app title. "X (close)" button appears next to the app title. Click the "X (close)" button to terminate the app.
Alternatively, hover over one of the Recent cards in the Recent UI or the app tile in Home UI. The "X (close)" button appears on the top of the card/tile. Click the "X (close)" button to terminate the app.
You can remove apps in the installed list from the webOS TV in Edit Mode. Long press the app tile to start Edit Mode and once clicking an "X" button, then the confirmation asks you again to remove the selected app. If selecting yes, you can delete the chosen app.