Small utilities, all of them local to your browser — nothing here uploads anything anywhere.
More are planned after launch, and the first in line is a form editor: declare your own bars as degrees and run the five substitution rules over them the way the pages here already do for the standards.
Anything that turns up here will follow the same rule as the rest of the site: it has to be about the tune and what gets played over it, not about an instrument. Tuners, metronomes and fretboard charts already exist, properly, on the sister sites, and a worse copy of one is not a tool — it is a detour.