This site is a map, so it ships one utility rather than a shelf of them: a colour theme builder, which changes how this portal looks and nothing else. It runs entirely in your browser and stores your choice there.
- Theme builder — pick a ground and an accent, and the whole portal follows.
Where the real tools are
Tuners, metronomes, ear trainers, chord finders, progression builders and the rest belong with the instruments they serve, so they live on the sites that teach those instruments. The directory says which site keeps which; the widest shelf by a distance is String Warrior’s.