I don’t know if this has ever been mentioned before but one feature that would be nice to have is a speed control on the audio. I almost never use the imbedded audio player now and instead use the music trainer app on the iphone because I can slow the text down when needed - up to 30% without losing pitch. Maybe I am an odd case and maybe I am not very proficient at picking up language by ear at full speed. But, I found that the ability to slow the text down provides me with 2 huge advantages: 1) it allows me to play over some passages that I simply cannot ever hope to make out at full speed or that frustrate me to no end and 2) I enjoy learning russian 1000 times more and consequently I study far more hours a day now than I ever did in the past. I can sometimes just slow the text now and instead enjoy the text instead of feeling like I am struggling through a hard lesson.
It is a pain to always download songs to the iphone and to have to manage the playback controls on the iphone instead of directly on the webpage. It would be awesome if such a feature was imbedded.
Also, it would be nice to have a user defined jump back distance on the audio player or have a couple of options. 10 seconds almost always seems too long.