Document Scanner & Manager is a TOTALLY free app for scanning documents like any kind of receipts, business cards, white board drawings, greeting cards, book pages etc. The app does NOT have any ads. After capturing the photo, you can crop it the way you want. The app also allows to select different filters. With categories, you can arrange your documents in better way.
Sharing of the final document can be done via email, iMessage, SMS/texting, printing etc.