App showing the RPM in an app window.
place this folder in Assetto Corsa app\python folder:
\assettocorsa\apps\python\demoapp
The app should be enabled, in Content Manager this app can be enabled via Settings -> Assetto Corsa -> Apps. Make sure the checkmark of this app is checked.
To view the app in game, click the app when hovering over your app-bar, this can usually be found when moving your mouse to the right side of your screen when ingame. Click demoapp. A Small window will now appear.