Swarm
When Foursquare launched its location game in 2009 at SXSW, it was super fun to play: you could “check in” at various places, and if you checked in often enough at a certain place, you could become its mayor – a position without any benefits. The app, called Swarm since 2014, is still around. Many people I know stopped using it, but I still check in if I don’t forget. It has a nostalgic feel for the time when the mobile app world was new and exciting, and the companies that created the apps were small and quirky.