One of the more subtle new features in iOS 9 is that you can now leverage Apple’s built-in iBooks app to save documents and web pages into PDF files. To access this, bring up the normal iOS 9 Share Sheet — the same one you would use to share something to Twitter or Facebook — and scroll over to the right side of the list and a “Save PDF to iBooks” option should appear.
Selecting the option will open iBooks and the document or web page you’re sharing should appear there as a PDF file in your iBooks library. From there you can organize it into a collection, print it, or send it out via email. Note that if you don’t see the “Save PDF to iBooks” option, tap “More” and ensure that it’s switched on in the list of sharing options. If it doesn’t appear in the “More” section, this means that the content type you’re sharing can’t be saved as a PDF.