Hello .. first of all thanks for the app and the effort to make it work on Mac
I have a MacBook Pro with Yosemite and I want to report a few things ..
First the application run slow and as other user have reported it crash on close
But regarding to the dual monitor there is an particular issue ..
I have the laptopt display at 3840x2400 (Retina set for space) and a external display on 1920x1080 ..
This is what you get when you open it on the laptop
The problem is when you move to the external monitor you get
Hope this help .. any other info you need let me know
Best regards