About three ago I got interested in location-based "check-in" apps like Foursquare and Gowalla. After starting out casually, and only occasionally logging my traverses with my phone, I now find myself racing to check in at restaurants. Indeed, my wife and I have an ongoing contest to see who can create unlisted places first.
Recently I happened upon another free check-in application called CauseWorld. It's similar to the other titles except that it offers real world value. Each time I check myself into a location, I pick up "karma points" that I can later redeem for donations to charitable causes, such as caring for abused animals, planting trees, and fighting cancer. More specifically, companies like Kraft and Proctor & Gamble end up doing the good deeds in exchange for looking at their ads and promotions.
A typical check-in might yield me five to 10 points with some getting more. For example, a few weeks ago I noticed that Sears was offering double karma points each time someone checked in. After a busy weekend of running around, I was able to feed a chimp with 100 karma points. On the lower end of the causes, 14 points is all you need to provide a meal through Feeding America.
One of my favorite things about CauseWorld is that it seems to have nearly every type of business or location already cataloged. Also, almost all brands or establishments listed have their official logo for easy recognition when checking in. Also, the interface is clean and intuitive enough that most people can just install and run.
Since the app uses GPS to determine your location, it's nearly impossible to "game" the system; you must present at a location in order to check-in. Users can check-in to a place once a day and they must wait a few minutes before checking into successive places. That's why it takes quite a while to hit every place in a strip mall.
Though the ads displayed by sponsors like Sears and Citi are unobtrusive and don't distract from the application, I'll gladly give up a little screen space to them as long as they're actually fighting cancer in my honor. If you're into check-in apps or feel like "doing your part," then I definitely recommend CauseWorld. Now if you'll excuse me, I have to go stop river pollution. I can't let my wife become a bigger humanitarian than I am.