Yes. Current lessons, practice and explanations are in English.

The available content for that course only. The app is free to download; each course is sold separately. Coverage and features differ by course—check the in-app information before buying.

Use the Apple Account that holds the purchase, connect to the internet, and select Restore Purchases on a course access screen or under Home → Purchases. Complete Apple's authentication and wait for the result. Restoring does not buy another course.

Check connectivity and allow the app to use it. Reopen and retry once. Finish Apple's prompts before leaving the app. A cancelled purchase does not unlock access. If Apple confirms purchase but the course remains locked, restore before attempting another transaction.

Set a daily budget for your current course, resume unfinished short practice, prioritize due review and follow one recommendation back to accessible teaching. The main task explains the reason for the plan and any work that does not fit.

No. The daily total estimates study effort from independent ordinary answers and effective concept recall, counted once per item per local day. It is not a stopwatch, a mastery score or a prediction of passing. Assisted study and independent simulations do not add to this estimate.

On your device, separate from Apple purchase entitlements. Resetting study progress does not refund purchases. Do not assume automatic cross-device study synchronization; preserve needed records before deleting the app.

Learning content and progress are stored locally. Prices, purchasing and restoring require Apple services; on-device learning does not mean every operation works offline.

Email support@codeverything.cn with the course/lesson/question identifier, app version and a short description. Redact personal information in screenshots. Never send passwords, verification codes or confidential exam content.