LinearMouse
Making external mice feel like they belong on a Mac
Per-device pointer and scroll tuning for macOS, free and open source. Each external mouse gets its own acceleration curve, scroll direction, and sensitivity — independent of the trackpad and any other connected mouse.
macOS treats every input device with one set of global pointer settings, which is why a $9 office mouse and a high-DPI sensor never quite feel right on the same machine. LinearMouse splits the controls per device. You can pick a linear curve (no acceleration), a custom curve, or one of the presets, and override scroll direction independently of the natural-scroll trackpad setting.
Per-app rules can adjust horizontal scroll speed in Final Cut, disable acceleration in a game, or invert the wheel inside a specific browser. Lives in the menu bar with near-zero footprint. macOS 13+, MIT-licensed.