Fluor2.5.1

Fluor automatically changes how your Mac’s Fn keys behave when you switch between applications, letting each program use the keyboard mode that suits it. A status-bar indicator shows whether the keys currently follow Apple’s default function-key behavior or act as traditional F1, F2, and F3 keys. You can choose the default mode Fluor applies whenever it runs, then assign different behavior to individual applications.

The active application and its rule appear in Fluor’s status-bar panel, where you can change that rule immediately. The Rules Editor displays all configured applications and lets you add, edit, or remove entries; adding one opens a file selector for choosing the application. Some programs, including certain Steam games, cannot be selected through that editor, so a separate panel lets you assign rules to any currently running application. Setting an application to the default behavior removes its custom rule from the editor, while disabling Fluor restores the keyboard behavior from before that application launched.

Fluor suits Mac users who alternate between software that benefits from Apple’s special keys and programs that rely on standard function-key shortcuts. Version 2.5.1 runs on macOS on both Intel and Apple Silicon hardware and is categorized under System Tools. It is freeware, and its code can be built from source, although the developer recommends that approach for people modifying or studying it rather than for ordinary use.