1.) Genuis Scan - Great scanner for regular documents and can be used with photographs. Available on iOS and Android. Free.
2.) Evernote Scannable Free, but you need to link to Evernote.
3.) Prizmo- Scanner with OCR and editing capabilities. Available on iOS. $9.99
4.) Scanner Pro - Available on iOS. $2.99
5.) CamScanner - Available on iOS and Android. Free, but you can purchase subscription for additional features.
6.) Shoeboxed- Primarily used for digitizing receipts.
This app is available for both iOS and Android. Free.