Docr - Docr is a free app for the iPhone smartphones that lets its users scan all of their documents into sharp images and, in the end, store them as PDF files.
Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.
Scanner Pro - Scanner Pro turns your iPhone into portable scanner in your pocket.
Wondershare PDFelement - All-in-one PDF editor
Quick Scan - A scanner utility that enables you to quickly scan documents and manually set the DPI level...
Foxit Reader - Foxit Reader is a free and light-weight multi-platform PDF document viewer.