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.
Sketch Mirror - Preview your iOS designs directly on your devices
Scanner Pro - Scanner Pro turns your iPhone into portable scanner in your pocket.
Crystal: Sketch Mirror for Android - Crystal: Sketch Mirror for Android is an application that is designed for viewing your sketch designs in real-time, navigate prototypes and download content related to the sketches for offline viewing.
Genius Scan - On The Go.
Flowkit - Sketch library for user flows/content maps/annotations