OS X mostly ignores the M4/M5 mouse buttons, commonly used for navigation. Third-party apps can bind them to ⌘+[ and ⌘+], but this only works in a small number of apps and feels janky. With this tool, your side buttons will simulate 3-finger swipes, allowing you to navigate almost any window with a history. As seen in the Logitech MX Master! - View it on GitHub