Questions, bugs, or feedback on the app — I read every email myself and usually reply within a day or two.
Which topics are free?
Measurement and Kinematics are free in full — every section, quiz, and flashcard, no time limit. The remaining 9 topics, all mock papers, the open-ended question bank, and the revision planner unlock with a single one-time purchase.
I purchased the unlock but it's not showing on this device.
Open the paywall screen and tap "Restore previous purchase." This checks your Apple ID (or Google account) for a prior purchase and restores it — make sure you're signed in with the same account you originally purchased with.
Does my progress sync across devices?
Not currently — progress, bookmarks, and your revision plan are stored locally on each device. Your purchase itself does sync via Restore Purchase, but study progress does not carry over automatically.
I found a mistake in the content.
Please email the topic name and what's wrong — content accuracy is taken seriously and corrections are usually shipped within a few days.
Where's the privacy policy?
See the Privacy Policy.