I will let you know if I have any success with the sync function; haven’t tried yet.
I have not tried to import a course yet. Do you mean like a SCORM file? Do you know a source for material that would be valuable to import, either free or fee-based? I haven’t had luck in finding much (just a few, college level and not applicable for poor ESL children.
Moodle app does seem to work for offline though, which is important. However, if I want to use the Khan Academy material on Moodle, its seems to me the videos would be easy, but the exercises would have to be entered into Moodle as quizzes by hand, a huge job.