Each app has its own policy describing exactly what it does with data. In short: none of them have accounts, ads or analytics, and none of them sell anything about you.
Estimates the carbon footprint of the page you're viewing. Sends only the domain you scan to the Green Web Foundation; everything else stays in your browser.
Copies a locator for any element you click, for writing automated tests. Makes no network requests; settings and recent picks stay in your browser.