Wasabi Sync currently requires TouchJSON. There are two versions of the static library in the iOS archive. One includes TouchJSON and one does not. If you already use TouchJSON and you don't want to use the version we compiled with, then use the one that does not include it. Otherwise, use the version that does.
Very soon, we'll be porting the code to use the built-in NSJSONSerialization in iOS 5.x+. When we do, the TouchJSON requirement will go away.
After you download the SDK, be sure to check out the getting started documentation for more information on how to add it to your project.