this is part of a year long effort to bring about an end to slavery. >> reporter: according to estimates, the number of modern day slaves ranges from about 10 million to 30 million people. the problem that widespread, it is easy to feel that individuals like you and i can't do anything to stop it. but we can, and the right apps can go a long way to help. you want to make sure the products you buy are not the product of slave labor. talking about both the materials used to make them and their manufacturer. that is where this app comes in. it is called free to work. it was developed by the not for sale initiative. it's a handy guide to help consumers make ethical choices. the app shows how companies around the world rate according to the labor practices. as you can see, there's a whole list of companies to choose from. for example, you can bring up adidas it scores an a minus or we can bring up godiva which