Citrius.Owin.Security.Foursquare is a OWIN Katana authentication provider for Foursquare.
Create a Foursquare app to get your unique Client ID and Client Secret from: https://developer.foursquare.com
Install-Package Citrius.Owin.Security.Foursquare
Add the following to Startup.Auth.cs (VS2013) or AuthConfig.cs (VS2012):
app.UseFoursquareAuthentication(
clientId: "",
clientSecret: "");
This product includes software developed at: Microsoft Open Technologies, Inc.