Support

Email support@stack-app.app and describe what happened and what you expected instead. If it is an account problem, write from the address on the account so we can find it.

• Check your spam or junk folder — confirmation mail lands there more often than it should.
• The sign-up screen has a Resend button; wait a minute before using it, since providers rate-limit repeated sends.
• Confirmation links expire. If yours is old, request a fresh one rather than reusing the old link.
• If the address has a typo, choose "Use a different email" and sign up again with the correct one.

The most common cause is an account that was created but never confirmed — Stack will tell you if that is the case and offer to resend the link. If you are sure the account is confirmed and the password is right, email us and we will look.

Progress is tied to your account, not your device, so signing in on another phone shows the same lessons and the same streak. A streak counts consecutive days on which you finished at least one lesson, and resets after a day with none. Completing a lesson you have already finished does not award XP a second time.

If something still looks off, email us with your account email and what you expected.

Open the Profile tab and choose Delete account. This permanently removes your login and your entire lesson history, and cannot be undone. Details are in the Privacy Policy.

Tell us which branch and level, and what you think is incorrect — that feedback is genuinely useful. Note that lesson examples are simplified for teaching and government rates change annually; see the Terms of Use for what the numbers in Stack are and are not.