Okay, after starting it for the 3rd time and not maximizing the app I could interact with the gui for a while. But then I clicked on Top-Level-Element Audio and couldn't click anything else anymore afterwards... By the way, trying to resize the window has the same effect like clicking fullscreen: The window area becomes mostly white with some grey rectangles in it. Only fix is to quit...

Looks quite good, but seems buggy on my retina macbook. First time I started it I couldn't click anything. Second time I started it I tried maximizing, which turned the screen white, had to quite again. Now I'll try for a 3rd time... ;-)

looks great.