The Seafood Guide is a free app from the widely respected Monterey Bay Aquarium's Seafood Watch program that can help you make environmentally-friendly seafood choices. Basically, it's an automatically updated, location-sensitive, and more detailed version of their popular pocket guide (30 million distributed to date). The Seafood Guide gives you an A-to-Z list of seafood for your region, which you can browse or search, all with one of three color-coded rankings: Best Choice ("abundant, well-managed, and caught or farmed in environmentally friendly ways"), Good Alternative ("an option, but there are concerns with how they're caught or farmed"), or Avoid ("caught or farmed in ways that harm other marine life or the environment"). You can even search by market name (for example, "icefish" will bring up Chilean Seabass.)
The guide provides a lot of detail for each entry, with pictures, market names, consumer notes, and an often information-packed summary--and any health alerts, if applicable, for hazards such as seafood with high levels of PCBs. The app also includes a Sushi Guide, and you can browse seafood for other U.S. regions. If you want contaminant-free, sustainably harvested seafood, the Seafood Guide can make your choices easy and even educational.