To start your first scan from within the app, tap the camera icon on the bottom left of the screen. Genius Scan works the same way on both Android and iPhone. To show you the basics of how a PDF scanning app works, I'll use Genius Scan. They have various features and quality, but they all work on the same basic principle of using your camera to capture the image and save it as a PDF. There are a number of PDF apps available in the app store.
The quality's not quite as good as a desktop scanner, so I do recommend you use a full featured desktop scanner for any document you need a high quality reproduction of, such as photos or legal documents, but PDF apps are perfect, though, for capturing basic documents and notes on the go. This app uses your camera to capture an image of your document and store it as a PDF. A great way to scan documents, if you don't have a scanner, or when you're on the go, is with a PDF app for your mobile phone or tablet.
