Scanbot - Scanbot is a mobile app that allows you to use your device's camera as a document scanner. The app is capable of scanning a large number of source materials, and it can handle QR codes as well.
Haystack Search - Haystack helps you make the most of your time, by searching all your files and documents in the cloud in one place. It's been built for privacy from the ground up, so your data isn't stored on a server, just your computer.
Scanner Pro - Scanner Pro turns your iPhone into portable scanner in your pocket.
MailJack+ - Send PDFs as postal mail
Genius Scan - On The Go.
Paperkit - Create and download custom graph, lined, or dot grid paper