Google Lens - Discover information about something by taking a photo
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.
GImageReader - gImageReader is a simple Gtk/Qt front-end to the Tesseract OCR Engine.
Scanner Pro - Scanner Pro turns your iPhone into portable scanner in your pocket.
OpenScan - FOSS Document Scanner
Genius Scan - On The Go.