I've been using 2 displays to do software development for many years now and found it makes things significantly easier. However, I've become increasingly irritated with the process of moving windows to different screens as I use them. This has been exacerbated by the fact that my new work laptop has a resolution that doesn't match that of the external screen, leaving disparate display sizes. I'm often moving applications back and forth in order to see more or simply organize them for more useful views.
Although it certainly isn't very new, I only recently discovered a very handy tool that solves this problem. Oscar's Multi-Monitor Taskbar is a free tool that adds a taskbar to secondary monitors. The additional taskbar shows the buttons for the applications that are on the same screen, while those buttons are absent from the main windows taskbar. It also adds a button to each window title bar next to the min/maximize buttons that performs single click window relocation between screens. This screen relocating can also be performed using shortcut keys (CTRL-ALT-LeftArrow/RightArrow). While the taskbar tool looks very useful, this implementation of it has some distracting side effects. The real taskbar flashes with partial button imagines when you switch between apps.
Fortunately, there is also a stripped down version of the tool that just adds the screen switching buttons. The one drawback I found is that this version lacks the shortcut keys. Regardless, a single click is considerably better than restore-drag-maximize.
Windows Phone 8.1 has my attention now
1 day ago