Jeff Wilcox via Twitter on the new version:
4th & Mayor update is out there. The latest version has a new set of category icons emphasized by your accent color, they should look pretty slick! Some phones though are very slow on first update, taking a minute at a blank screen - sorry! Investigating.
Foursquare has matured since its introduction to the web many years ago - from a simple check-in service to a search and recommendation engine based around location. It's great to see that 4th and Mayor has kept pace with these changes!
You can download your copy from the Windows Store, or via the AAWP App Directory.