Depending on what I am doing, I code on my larger resolution monitor (more lines/columns!) and use the smaller resolution monitor for the browser & reference.
At work it is the opposite, because my laptop is some high resolution (1900x1600 or something) and my external is only 1280x1024. LUCKILY it does landscape/portrait, so I can view long pages nicely.
I usually use the external on landscape, and have it on a box, so it is above my monitor, and keep email (groupwise = crap!) open, plus test pages, because of the lower resolution, and code on the laptop screen.
At home, the external is on the left of the monitor, and runs at 1280x1024, and the laptop is 1024x768. I vary how I do things at home...
I use no utilities to manage it. None needed on either setup. (work or home)