Think

Think is a small application for Mac that places one window or application in the foreground with a gradient background behind it, helping you stay focused and avoid distractions.

The rest of the application windows stay behind the colored background. This background is black by default, but you can set a custom color from the control panel.

In Think, you can also select the opacity of the background, as well as the application you want to focus on. By clicking on the colored background, the window Think is working with will be highlighted.