The app is open source and doesn’t need to be installed. When you run it, to goes straight to the system tray. By default it will show keystrokes as well as mouse clicks, highlighting which mouse button was clicked. The first thing you want to do after running the app is customize it. Double-click the app’s icon in the system tray to open its settings.
On the General Tab, you can select where the keystroke shows on your screen. Use the top, bottom, left, and right offset sliders to position the visual. Carnac supports multiple monitors so you can choose which monitor the keystroke should be displayed on. Be careful with this setting because if you offset it too much from all sides, it might cut the visual off.
Once you’ve positioned the app’s visual, go to the Keyboard tab. Here you can customize whether the app will show all keystrokes or just those that include modifier keys. You can also customize the visual, its font size, opacity, and the color.
The Mouse tab is where you can customize how mouse clicks are shown on your screen. If you don’t want the mouse clicks to show, uncheck the ‘Show mouse clicks’ option. This option is a bit buggy though so if it doesn’t apply, set the value of the Stop Opacity slider to 1, exit the app, and run it again. That should do the trick.