With more than 1 million apps in the Apple and Android stores, it would be easy to assume we are nearing the limit of developers to come up with new creations. That would be a mistake. The latest example: Apps aimed at fighting human trafficking. Yes, they exist and more are emerging as social entrepreneurs attempt to use technology to battle what they see as the forces of evil. A group of government agencies and private foundations calling themselves Partnership for Freedom has set up a competition with the not-so-catchy name Rethink Supply Chains challenge. What is grabbing attention is $500,000 in prize money that will be awarded for the best technology solutions to combat the use of slave labor. Rising awareness among global companies of labor abuses and new laws requiring steps to ensure fair labor practices across supply chains are spurring a new industry for technologies that help them enforce supplier rules. Existing apps already help consumers get an idea of the scope of human trafficking. Made in a Free World, for example, created the Slavery Footprint app that generates estimates of an individuals reliance on slave labor from data on trafficked humans and labor-abuse rates at manufacturers and suppliers. Justin Dillon, chief executive officer of Made in a Free World, is not shy about telling people that for all his efforts, his lifestyle still requires 47 slave laborers - a number hes determined to get to zero. Thats what drives me, he says.