What you have read
Your progress record
Every answer is filed against its own question, its lesson and its sheet, so a single item can only ever credit the lesson it belongs to. Nothing here is uploaded: clear your site data and this page is empty, which is why the export button exists.
The progress record is part of Premium
Per lesson and per sheet accuracy, weak area targeting, the printable completion record and JSON export and import are the paid layer. The daily drill of 10 items, all sixteen sheets, every reference page and every guide are free forever.