When Apple first passed out those development restrictions on using third-party platforms to create iOS apps, Unity was one of the third-party services that could have been frozen out (though Flash was obviously in everyone's minds). The team behind the popular game development environment assured everyone Unity was safe, but according to the rules as stated, the rest of us weren't so sure.
Now that Apple has officially relaxed that policy, however, Unity's David Helgason is doing the equivalent of a victory dance on the company's official blog, saying that Unity resp