Troubadour Tour Board
A game you play by wandering around a bustling area with your phone "checking in" to places as you go.
It's a Google App Engine app written in Go. You want the App Engine Go SDK.
Not included w/this source code: need to set app keys for using foursquare API and for OpenID Google login. For local testing, you don't need the Google login, but you still need a 4sq API key. I have a handy .sh script that looks like
...but instead of SECRET and REDACTED it has the app ID and key.