Gesturefy - Customizable mouse gesture addon, which supports over 40 different actions. Features:
PiPer - A DIY Minecraft computer to build gadgets
Strokeit - StrokeIt is an advanced mouse gesture recognition engine and command processor.
Helium - Helium lets you accept payments by credit card for anything you want to sell online.
crxMouse Chrome Gestures - Boost browsing productivity with mouse navigation shortcuts - simple Mouse Gestures, Super Drag, Wheel Gestures, Rocker Gestures.
PiP for Mac - Always on top window preview similar to the popular windows only OnTopReplica