The Pocket Environmentalist

17 smartphone apps that help save the planet

11. PaperKarma

Sick of getting junk mail? PaperKarma is here to help. Simply snap a photo of the offending flyers and the app takes care of the rest by notifying the sender that you don’t want it. Its motto says it perfectly: “Kill unwanted mail, not trees.” Note: at this time, the app is only available in the United States.
(Free; Apple, Android)