The data in the Australian-developed app comes from the Guide To Ethical Supermarket Shopping 2010, and includes background information on the companies behind 2,800 products, including their environmental and social policy records. It's a useful tool if you don't want your money going to companies with questionable practices.
Shop Ethical! runs on iPhone or iPod Touch, and costs $4.99. (Alas, ethical shopping rarely turns out to be the cheapest option.)