Zuck doesn't even think tablets are mobile.

Based on Foursquare’s estimations, the iPad will no longer stand alone in the tablet race. Foursquare finally created a tablet app, but has curiously designed it exclusively for Sony’s new Tablet S and P.

The strange part is, in May, Foursquare head of product Alex Rainert said Foursquare did not have the resources to develop an iPad app and would continue to devote its resources to enhancing the iPhone app experience instead. So why would Foursquare commit resources to a new tablet, instead of the market leader?

UPDATE: Dens replied on Twitter to let us know what went down. This app wasn't built in-house by foursquare, but by Sony, using the foursquare API and their blessing. So foursquare is more a collaborator than a creator here. 

Although Foursquare apps do exist for the Blackberry Playbook and HP Touchpad, they were built by third party developers.

The Sony Tablet S and P will come preloaded with a version of the Android app that is designed exclusively for tablet format. The tablet version of the app will likely differ from its smart phone predecessor in that it will focus more on the game’s “explore” function than checking in.

In the realm of pure speculation, it is not unusual for hardware or OS makers trying to woo developers to their platform to subsidize the cost of building an app. Microsoft astroturfed the app environment for their Windows 7 phones, and it wouldn't be surprising if Sony is doing the same for their tablet.

We have reached out to Foursquare for comment and will update with any reply.

Microsoft faces a sort of Catch-22: developers are unlikely to devote their resources towards Windows 7 till its a proven market, and the market won't expand unless there is healthy number of apps.

This can lead to some awkward situations. Microsoft paid the development costs to ensure Foursquare was part of their initial launch. But the app quickly fell behind the updated versions for Android and iOS and even stopped working for many users back in March.

Yesterday Microsoft changed the download link to the Foursquare app and began officially pointing users to 4th and Mayor, a popular third party created by Foursquare fan, and Microsoft employee, Jeff Wilcox.

When your own employees are the only one who care enough to keep popular apps up to date, perhaps because they are the only ones using your phone, its time to start priming the pump again with some cold hard cash.