Habit List - Create good habits and break bad ones with the app that keeps you focused.
MilkDrop - 3D audio visualization plugin, compatible with WinAmp plugin API
Momentum - Agile goal and performance management
projectM - projectM is an LGPL'ed reimplementation of Milkdrop under OpenGL.
Streaks - The to-do list that helps you form good habits.
Magic Music Visuals - Fully-customizable and highly responsive visuals for live and recorded audio & MIDI.