I've looked high & low for a FourSquare app for the BlackBerry PlayBook, but apparently I wasn't looking in the right places. While looking recently in "Recently Updated" apps on App World, I noticed FourPlay.
FourPlay For PlayBerry PlayBook
is exactly what you'd expect from a FourSquare app on your tablet. This 3rd party Foursquare app brings all the features you'll find on your official FourSquare app found on your BlackBerry Smartphone. I was amazed at the fact that my location was more accurate within this app than it is when I use my Bold 9900.
With many tweaks/updates rumored to be coming to a future build planned to be released around the same time as PlayBook OS 2.0, & with no plans official 4Sq app on the horizon, this application is a must have for anyone who checks-in often.