- Localvore: What's in season where you are? Eat local, eat seasonal and reduce your food miles. $2.99 on Apple Store.
- The Extraordinaries -- On-demand crowd-sourced volunteerism via smartphones (not yet live).
- Monterey Seafood Guide: this I've blogged about before. Free on Apple Store.
- SquarePeg (they tied into the SocialActions database)
- 3rdWhale - LBS green-business finder. Free on Apple Store. Disclaimer: I now work here as the VP of Mobility & Sustainability.
In addition, there are a number of good feature phone apps that use SMS too. Notably - my favorite organization in this space -- Kiwanja, which does a lot of good work in healthcare in Malawi. Check out their FrontLine SMS app - way cool, super useful to humanity!