First, you sign in to the Google Stack app, using your Google account. Then tap on the + button in the bottom-right corner of the screen. You can scan and import items in three ways: the PDF option for already-digitized files, the Gallery option if it’s a photo, or the Camera option to create a digitized version of an actual document. Using Camera is akin to taking any smartphone pic: Place the paper on a well-lit, even surface, hold the phone steady, and tap the Scan button. The app automatically crops and sharpens the image.