Support
What Chiong Lab is
A revision app for O-Level, GCSE and IGCSE students, covering all twenty topics of the O-Level Pure Physics syllabus, listed in the app under LEARN. Each lesson is built around a diagram you can drive — move a slider or flip a cell and the current, the forces and the meter readings all respond — followed by exam-style questions with the working shown.
Deleting your account and your data
In the app. On the phone: ME → Settings → Delete account. On the website: MORE → Delete account. That erases your identity, sessions, progress on the server, onboarding answers, attempts, notebook, league seats, friend links, feed posts and comments. Progress stored on the device itself is a separate copy — use Reset all progress on the same screen to erase that.
We reply to confirm, and delete within 30 days of confirming. We ask you to write from the account's own address because that is the only way we can tell it is your account and not somebody else's.
What is not deleted. If a report has been filed about something you wrote, the moderation record survives deletion: it keeps the words that were reported and the fact that they were reported, and nothing else about you — no email, no password, no progress. A moderation record that disappears on request would not be a moderation record. This is set out in the Privacy Policy under Reports and moderation.
Common questions
Do I need an account?
No. Open the app and start as a guest, and every lesson and question is there. An account is optional: it is how XP, streak and lesson progress follow you to another device, and it is what opens the weekly league, friends and the feed. You must be 13 or older to create one.
Does it need an internet connection?
Every lesson and question is inside the app, so revision works offline. Creating an account, signing in, leagues, friends, the feed and classes need a connection.
Where is my progress stored?
On your device. If you create an account, a copy is also stored on our server so you can sign in elsewhere. Guest play is never uploaded.
Can I get a copy of my data?
Yes. ME → Settings → Your data on the phone, or MORE → Your data on the website, downloads everything we hold about your account as a file you can keep.
Somebody wrote something horrible
Report it, and a person will read it. You can report a student from their profile, and you can report a single comment from the comment itself — press Report at the end of the comment's row. You can also block a student: they will not be able to find you in search, open your profile or send you a friend request, and they are not told. Undo a block under Blocked students.
Who can see what I write?
Comments are visible only to the person whose milestone you commented on and to their friends. They are never public and never appear to a signed-out visitor. Your profile is private until you turn Public profile on yourself.
I deleted the app. Can I get my streak back?
If you only played as a guest, no — that copy lived on the device. If you had an account, sign back in and the server copy of your progress returns.
When are the other topics coming?
The full roadmap is listed inside the app under Subjects. Topics still being written are marked there, and they arrive in updates.
A question looks wrong to me
Please tell me. Getting a mark scheme wrong in a revision app is the worst kind of bug, and I would rather hear about it than not. You can send it from inside the app — Report a bug or idea on the settings screen — or email the address above.
Reporting a problem
If the app crashes or behaves oddly, it helps to include:
- Your device (for example, iPhone 14) and iOS or Android version
- What you were doing when it happened
- A screenshot, if you have one