From RealityRipple Software:
Mouse Manager is a small tray icon-based utility which lets you quickly and easily set the fourth and fifth buttons on a 4 or 5 Button mouse to any key or key combination you choose. Mouse Manager lets you emulate keyboard commands with the click of a mouse button. A profile system lets you quickly choose between previously created key emulations through the tray icon menu. Mouse Manager will detect clicks from the fourth and fifth mouse button (tested on IdeaZon Reaper Edge Laser gaming 5-button mouse and Logitech m325 using the tilt wheel) and emulate the repeated pressing of keyboard keys. Multiple keys may be sent at the same time, allowing you to quickly send complicated keyboard shortcuts with a single click.