SensibleSideButtons lets you add functional side navigation buttons to your third-party mice in macOS. This tool makes your side buttons behave like bona fide navigation keys. Navigation now works in practically any application with a history, even if there aren't any keyboard shortcuts bound to forward and back. Navigation commands are sent directly to the view under your cursor. There's no blinking menu bar, no annoying noises, no fear of errant keyboard shortcuts messing with your workflow. Best of all, the code is native, clean, and very simple.
