Checking…
Sync is unavailable
The progress service is not responding. This changes nothing about your lessons — progress is stored in this browser first and syncing is only ever a copy.
Sync is not open yet
The progress service is running, but email delivery is not configured on it yet, so a sign-in link would be created and never sent. Rather than take your address and do nothing with it, the form is switched off until that is fixed.
Nothing is lost in the meantime: marking lessons complete works exactly as it always has, saved in this browser.
Sign in with a link
Enter your email and we will send you a sign-in link. There is no password to choose, forget or reuse, and we never store one.
We store your email address and which lessons you have completed. Nothing else. See the privacy page for the full list, including how to delete it.
Check your email
If is a valid address, a sign-in link is on its way. It expires in 15 minutes and works once.
Nothing arrived? Check spam, then.
Signed in
You are signed in as . Lessons you mark complete on any device now appear on all of them.
Signing out leaves this browser's progress alone. Deleting removes your address and your synced lesson records from the server for good; progress already in this browser stays.