On the third monitor I have the actual app running (be iOS simulator, browser window or normal native app, virtual machine, whatever)
And I have a fourth monitor with team chat, documentation, sourcetree and "general browsing".
When I work I just keep my email and other IM closed. Those are distracting in single or multiple monitor mode anyway.
I have two horizontally stacked 27' monitor at the center and 1 vertical 27' monitor on each side. This provides a quite compact work area, at least I can see the whole estate without moving my head too much.
I am now traveling and on a single screen, and I am more distracted that ever, because I cannot keep my work "open" all the time and as soon as I switch to another window, it's full screen and covers everything.