Even the tutorial on the site (after signed up and logged in to developer site) uses the Puff Puff as example. So make sure you read my previous post about how to run Puff Puff in your iOS5 simulator.
[UPDATE 20/01/2012] Thanks to Daniel Shir and Shai Magzimof from Nextpeer who pointed out to me that Nextpeer does support other games not using Cocos2D. I checked their developer site again this morning and confirmed that it's my mistake - sorry for that.
What I should say is, there's only a video about how to use Nextpeer using Puff Puff as example (which uses Cocos2D) - would be more handy if they can also provide a few more videos about other games, start up a forum, add more examples, FAQ, more technical info targeting developers of different skill levels,....etc.