Genius Sign - iOS document signing app, from the makers of Genius Scan
Tiny Scanner - Fast and easy to use mobile document scanner.
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.
TurboScanner HD - TurboScanner HD is an app for iOS that enables you to convert the iPad or iPhone into a useful scanner and also serves as small fax or air printer in your pocket.
DocScan - DocScan is a PDF document scanner application for the iPhone smartphones that lets the users to scan their documents and get them in the PDF files.
Genius Scan - On The Go.