Small utilities, all of them local to your browser — nothing here uploads anything anywhere.
More reading and writing tools are planned for after launch. A chart editor is first in line: type bars of digits, pick a key, and get the realization back, which is the one thing this site's own engine already does for its four published charts and does not yet do for yours.
Anything that turns up here will follow the same rule as the rest of the site: it has to be about the page rather than about an instrument. Tuners, fretboard charts and capo calculators already exist, properly, on the sister sites, and a worse copy of one is not a tool — it is a detour.