Might be a really stupid question but anyone got any idea how to get rid of the black toolbar appearing when running my application. I'm using Template10 as well.
That's buttons for debugging your application.
If you deploy your app and run it - your app will run without them.
Watch this thread if you want to manage:
How to remove the “Go to live visual tree” / “Enable selection” / “Display layout adorners” overlay when debugging?