Interesting timing. For some reason, 3G was down in my area for a little while earlier today when I was trying out the app at work.
I was surprised to find that it did actually work on Edge. To make it better, I went into the app options and changed 'quality' to SQ vs HQ. Doing so definitely impacted the video quality but it was still very usable. It kind of reminded me of watching video during the 56kb dial-up modem days. The first minute of two were choppy as it would freeze for a few seconds and then pick up. I assume the app was trying to buffer or something because after this, it no longer froze.
I did a speed test and found that my Edge connection was only in the 75-80Kbs range- so pretty slow. Given that I expected it not to work at all, I was fairly happy with the result.