Save the questions first
On the website, open Practice and choose Download offline questions. Wait for a ready status before disconnecting.
Check voice and video
The Android app includes local speech recognition. Install an English device voice for spoken questions, and download the course videos you want to use. Browser recognition can still require internet.
Keep a progress backup
Use Export progress backup on the practice page before clearing browser data. Store that file privately and restore it on the device where you want to continue.
Open offline tools