App support

Lesson content is downloaded from our servers, so the app needs an internet connection to open material you have not read before. Check your connection, then close and reopen the app. If a specific topic still fails while others work, email us the exact topic name — that tells us which file to fix.

Lessons you have already opened are cached on your device and stay readable without a connection. Opening a topic for the first time needs internet access. Full offline download of the entire course is the feature we are asked for most often and it is in development.

First, make sure you are signed in to the same Google or Apple account you bought with, then reopen the app. If it is still locked, email us with the order number from your Google Play or Apple receipt and we will sort it out.

Yes. Google and Apple run separate stores with separate payment systems, and neither can see a purchase made in the other. This applies to every paid app on both platforms, not just ours.

Refunds are handled by the store you bought from, not by us — we have no ability to issue or reverse a payment. Use Google Play refunds or Report a Problem on Apple, within their time limits. If something is broken, do email us too: we would rather fix it than have you request a refund.

Please tell us. Send the app name, the topic, and what is wrong, to mail@ehsanur.com. Corrections are published in content updates and reach you without needing an app update. This is genuinely useful to us and we act on it.

Often, yes. Requests shape what gets written next, so send them.

Quoting a passage in a study group, a class, a forum answer or your coursework, with attribution, is fine. Republishing the course, in whole or in substantial part, is not. See our Terms of Service.

There is no account to delete, and everything the app saves is on your own device. See the data deletion page for the details.