I have recently updated my homebrew metronome for the Nintendo Wii. I have added a graphical interface (GUI), a practice timer, and the ability to set the number of beats in a measure. Firstly, I designed the interface from scratch in Photoshop, then I used libwiigui to help me create my first GUI ever.
You may download the Metronome here and the source code here. It is also available for direct download on the Wii through the Homebrew Browser. As of this writing, this has been downloaded over 25,000 times.