I found two issues in your User Interface: 1. Whenever I clicked on the 'Next Section' button, the left panel automatically moved to the top of the lesson. So, I had to go back and move the contents of the left panel to the section where I was reading in the right panel. Please ask your programmers to STOP doing that. Let the left panel stay where the student had placed it. I know the programmers have done that to show the updated progress meter. But, I was NOT interested in knowing that everytime I clicked on the 'Next Section' button. 2. When the audio goes from one subject of the lesson to the following subject, there is NO GAP in the audio. Please add a gap of a couple of seconds so that a student has enough time to scroll down to the text subject. I liked your decision to not place any session time limits on the student. I was able to stop in the middle of a session for several minutes whenever I needed to do something else, such as taking a incoming phone call.