Your app can receive a notification after certain users check in on Foursquare. You can use our User Push API to be notified every time one of your app’s users checks in on Foursquare or use the Venue Push API to be notified every time a user checks in at one of the venues your app’s users manage.
To start receiving pushes from us in your app, go to your app’s settings page, select the appropriate option in the drop-down under “Push API,” and enter values for the push URL and push version fields. After saving this app’s settings, whenever an appropriate check-in triggers a push to your app, you will start seeing POST requests from Foursquare to the push URL you specified.
For more specific details, see “Activating” under our Real-Time API detailed documentation.