Print to PDF was a $4 app that arrived in August 2011, letting users print web pages, photos and e-mails as PDF documents. As long as the app was running in the background, a “Print to PDF” option would appear in Apple’s built-in printing feature. (Image from TIPB)
Violation: Apple told the developers that they were not allowed to use AirPrint to print documents as PDF files.
Jailbreak Alternative: TruPrint has PDF printer functionality, among other features.