Description
GC Controller Test is a simple homebrew to test your Gamecube controllers (buttons, triggers, sticks, rumble motors).
It is available for Wii and Gamecube.
Screenshots

Downloads
Version 1.2 (Wii version) : download from my website or see attached files.
Version 1.2 (Gamecube version) : download from my website or see attached files.
Changelog
Version 1.2 : corrected a small error
Version 1.1 : added multiple controllers support (press a button on a controller to switch to it), tweaked the layout.
Version 1.0 : first release.
Source code
The source code is available on Github.