Text recognition, translation, the writing assist and transcription download a model the first time they are used. Your files are never sent.
The map editor draws your features over tiles from openstreetmap.org.
Used as the author of comments and replies you add.
Most sessions never need this. Two people whose networks cannot be connected directly need a relay (TURN) server to pass the document through, and this app runs none: you can point it at your own. It is stored in this browser, in plain text, like the rest of these settings.
Omnitext opens and edits practically any file, entirely in your browser. No account, no upload, no tracking.