Authentic CSR or greenwashing gone wild? It's not always easy to tell. But a growing number of tech tools make it easier to use your purchasing power for the greater good. Whether your goal is to swap rather than shop or learn to pause before making a purchase, there's–what else?–an app for that. The ones on this list, along with two innovative plug-ins, offer a range of ethical-shopping solutions. Discover where to source eco-style on the go, how to turn a buying spree into philanthropy, and a slew of social-good services in between.