I suspect most people use the Function Keys as the default that Apple prints right on the keys. After all, adjusting the brightness, switching windows, and controlling multi-media are pretty useful. But there’s a large contingent of power-users who want to customize their F-Keys to do various tasks… particularly designers using InDesign, Photoshop and Illustrator, where you might assign any number of tasks to them.

Fluor for macOS is a nifty little utility that allows you to automatically change the behavior of your Mac’s keyboard F-Keys based on what application you’re using. A menubar icon indicates which F-Key mode you’re currently in, and provides access to the prefs which allow you to set up Rules for individual apps.

Fluor is open source and completely free