The Toolz.dev extension holds everything it knows on your own device.

STORED LOCALLY, NEVER SENT
Your favorited tools, your recently opened tools, and a cached copy of the
public tool catalogue. These live in local extension storage, are never synced
to an account, and are deleted when you uninstall the extension.

WHAT IT SENDS
One request a day to toolz.dev/tools.json to check for newly added tools. It
carries no account, no identifier, and nothing you typed. When you open a tool
from the extension, the link carries ?ref=ext so we can count extension usage;
that is an ordinary page visit.

WHAT IT NEVER DOES
It cannot read or change the pages you visit: it requests no host permissions
and runs no content scripts. It collects no analytics and builds no profile.
The tools that run inside the popup work entirely offline, and what you paste
into them never leaves your browser.

Full policy: https://toolz.dev/privacy