From the blog post:
With the newest version of the application you can use your NFC enabled phone to check-in automatically by just tapping and NFC enabled/tagged poster. No more tedious steps of launching an application waiting for location fix, connecting etc... With NFC this is all done with a simple tap.
Furthermore, the developer made it even easier for the user to check-in - without the need to have the app running - just tap and the app starts automatically and checks you in. Pretty awesome and again demonstrating the convenience of NFC! In a separate post Andreas explains how as a developer you can implement application autostart .
Foursquare with NFC support is available in the Nokia Store for Symbian NFC enabled phones (download Symbian version here, N9 support coming soon) . And the best thing about it is that it is not a separate application just for NFC sake. Developers simply added the support for NFC to the existing application version!
Symbian phones with NFC currently number six: the Nokia C7/Oro/Astound, plus the 700/701/603, and all future Nokia smartphones going forwards will also have NFC baked in.