Privacy notice — MugCorner

Who we are

MugCorner is a maths practice website run by T-Leng Tuition (UEN 53533541E) in Singapore. We follow Singapore's Personal Data Protection Act (PDPA). Our Data Protection Officer is T-Leng, the owner of T-Leng Tuition. For any question or request about your data, email tlengeng@mugcornersg.com.

What we collect

Your account: your email address and password (stored scrambled, so even we can't read it).
Your profile: a nickname you choose, your level and stream, and your school if you choose to add it.
Your practice: the answers you type, whether they were right, which hints you used, and your mastery for each topic.
Payments (if you or a parent buy Plus): the payer's name and email, billing country or postcode, the plan bought and whether payments went through. Card details go straight to our payment provider, Stripe; we never see or store them.
Messages you send us through the contact, feedback or "report a problem" forms, or the short experience survey: what you write, the email and name you give, and (for question reports) the question on screen. Survey answers also carry your level, stream, and roughly how long you have practised. We use these only to reply and to fix and improve MugCorner. To know when to offer the survey, your device counts how long you have practised (kept only in your browser).
How you found us (optional): your answer to "How did you hear about MugCorner?" and the short code on the link you first came in on (for example "ig" for an Instagram post). We only count these to see which posts and groups work.
Notes you upload (when that feature arrives): the photos and the labels you give them.

We do not collect your location, your contacts, or your real name unless you put it in your nickname (please don't).

Why we use it

To log you in and keep your progress safe.
To mark your answers, spot the mistakes you make, and pick the right hints and next questions.
To remind you when a topic is due for revision.
To show leaderboards, but only if you switch that on.
To take payments for MugCorner Plus and send receipts.
To email you about your account, for example when your Plus trial is about to end (with a link you can pass to a parent).
To send revision reminders to your phone or computer, only if you turn them on in Settings. We keep the address your browser gives us for this, and delete it when you turn reminders off.
To fix bugs and improve the questions, using results with names and emails removed.

Who can see it

Other students only ever see your nickname and points, and only if you opt in to leaderboards. You can switch this off any time.
Your tutor sees your progress only if you give them your link code (under My Tutors). They see your topics, levels, scores and WA paper results, and can't change anything. You can remove a tutor or make a new code at any time.
A parent with your payment link sees only your nickname, level and stream, and what Plus includes, so they can pay for it. The link stops working after 14 days or once Plus is paid for.
Service providers that run the website for us: Supabase (database and logins), Vercel (web hosting), Google Workspace (email), Resend (emails from the site) and Stripe (payments). They may store data outside Singapore, and they must protect it to a standard comparable to the PDPA.

We never sell your data, and we never share it with advertisers.

If you are under 13

You need a parent or guardian's permission to use MugCorner. Please show them this page before you sign up. Parents can contact us at any time to see or delete their child's data.

Cookies

We use cookies to keep you logged in, to remember your colour theme, and to remember the short code of the link that brought you here (kept for 30 days). There are no advertising cookies and nothing that follows you around other websites.

We count visits with Vercel Web Analytics, which uses no cookies and doesn't identify you: it records the page, the site you came from, and your country, browser and type of device. Private links (such as a payment link) are counted without their code.

How long we keep it

We keep payment records for as long as tax law requires (currently 5 years), even if the account is deleted. We keep your other data while your account is active. If you ask us to delete your account, or you don't log in for 2 years, we delete your personal data within 30 days. We may keep results with your name and email removed to improve the questions.

Keeping it safe

Your data is encrypted when it travels and when it is stored. Each student can only see their own work, and answers are marked on our servers. If a data breach ever affects you, we will tell you (and your parent or guardian if you are under 18) and the Personal Data Protection Commission as the law requires.

Your rights

You can ask us to:

show you the personal data we hold about you;
correct anything that's wrong;
stop using your data and delete your account.

Email tlengeng@mugcornersg.com and we'll reply within 30 days.

Changes to this notice

If we change how we use your data, we'll update this page and tell you when you next log in.

What we collect

Your account: your email address and password (stored scrambled, so even we can't read it).

Your profile: a nickname you choose, your level and stream, and your school if you choose to add it.

Your practice: the answers you type, whether they were right, which hints you used, and your mastery for each topic.

Payments (if you or a parent buy Plus): the payer's name and email, billing country or postcode, the plan bought and whether payments went through. Card details go straight to our payment provider, Stripe; we never see or store them.

Messages you send us through the contact, feedback or "report a problem" forms, or the short experience survey: what you write, the email and name you give, and (for question reports) the question on screen. Survey answers also carry your level, stream, and roughly how long you have practised. We use these only to reply and to fix and improve MugCorner. To know when to offer the survey, your device counts how long you have practised (kept only in your browser).

How you found us (optional): your answer to "How did you hear about MugCorner?" and the short code on the link you first came in on (for example "ig" for an Instagram post). We only count these to see which posts and groups work.

Notes you upload (when that feature arrives): the photos and the labels you give them.

We do not collect your location, your contacts, or your real name unless you put it in your nickname (please don't).

Why we use it

To log you in and keep your progress safe.

To mark your answers, spot the mistakes you make, and pick the right hints and next questions.

To remind you when a topic is due for revision.

To show leaderboards, but only if you switch that on.

To take payments for MugCorner Plus and send receipts.

To email you about your account, for example when your Plus trial is about to end (with a link you can pass to a parent).

To send revision reminders to your phone or computer, only if you turn them on in Settings. We keep the address your browser gives us for this, and delete it when you turn reminders off.

To fix bugs and improve the questions, using results with names and emails removed.

Who can see it

Other students only ever see your nickname and points, and only if you opt in to leaderboards. You can switch this off any time.

Your tutor sees your progress only if you give them your link code (under My Tutors). They see your topics, levels, scores and WA paper results, and can't change anything. You can remove a tutor or make a new code at any time.

A parent with your payment link sees only your nickname, level and stream, and what Plus includes, so they can pay for it. The link stops working after 14 days or once Plus is paid for.

Service providers that run the website for us: Supabase (database and logins), Vercel (web hosting), Google Workspace (email), Resend (emails from the site) and Stripe (payments). They may store data outside Singapore, and they must protect it to a standard comparable to the PDPA.

We never sell your data, and we never share it with advertisers.

How long we keep it

Keeping it safe