Jeff CarlsonContributor, Macworld

Author and photographer Jeff Carlson (@jeffcarlson, jeff@necoffee.com) is the author of Photos for OS X and iOS (Peachpit Press) and Take Control of Your Digital Photos on the Mac (Take Control Books), among many other books. He’s also a columnist for the Seattle Times, a contributing editor at TidBITS, and writes for publications in addition to Macworld such as Lynda.com.

gfxCardStatus 2.1

With gfxCardStatus, you can see when your dual-video-card-equipped MacBook Pro uses each GPU. You can even force the laptop to use integrated graphics when you're trying to conserve battery power.