Simple math first. Excel when it saves time. Mistakes return later.
Correct attempts0
Need review0
Mastered0
☁ Cloud progress & backupInitializing…
Your progress syncs to a free Cloudflare D1 database using a private 64-character recovery code. Copy the code to restore your progress in another browser. Keep it secret: it acts as your login.
The site stores a hashed identifier in D1, not your recovery code. Browser data is a local fallback; backups protect you against lost codes and accidental changes. Uploading an updated app to the same domain does not erase D1 records.