Apple giveth and Apple taketh away.
According to Print to PDF's official website Apple has removed the iOS app Print to PDF from the App Store. The application allowed users to save their emails, attachments, websites, and photos as PDF documents by adding "Print to PDF" as a printer to Apple's built-in printing feature.
However, when Apple figured out that Print To PDF accomplished this by using Airprint, Apple's wireless printing feature, Apple yanked the application for The App Store.
We regret to inform you that as of August 26th, 'Print to PDF' is no longer available on the Apple App Store. On August 24th, we received a call from Apple Developer Relations telling us that we are not allowed to use AirPrint as a way to print documents to PDF and that for this reason the app could no longer be available on the App Store.
Source: PrintToPDF.com and iPhoneHacks