Fluor

Fluor runs in the macOS menu bar and automatically switches the behavior of the keyboard’s function (fn) keys when the active application changes. It shows an icon indicating whether the keys act as Apple’s default controls or as standard F‑keys, and it can apply a default mode on launch. Users can add, edit, or delete per‑application rules through a graphical editor, selecting applications via a file chooser or by choosing from currently running processes. The status‑bar menu also displays the active application and its associated rule, and it allows the app to be disabled, restoring the previous keyboard behavior. Fluor is distributed as a signed macOS bundle, installable via a DMG or Homebrew Cask, and is released under the MIT license. It is intended for macOS users who need different fn‑key functionality across apps, such as developers, designers, or gamers.