If you told me that you'd never heard of Foursquare, I'd call you a liar. We've all see the cross-posts from Foursquare on Twitter and Facebook. I'd find it hard to believe that you had gone your entire life without seeing Foursquare notifications, but if you told me you didn't know what Foursquare was for, that I could believe. Foursquare, at its heart, is a fairly straightforward location-based game.
Before Facebook started offering its own 'check-in' feature, there was Gowalla and Foursquare, both of which are still widely used. The Gowalla app for Android received an update today to version 4.0 which brings "a brand new version of Gowalla! Tons of new features including Guides, Stories, and Lists, and more. [sic]" to the table. No, really. That was directly from the changelog in the Market listing. The only entry in said changelog, to be exact.