If you don’t like the scan, just refresh the image for another take. For documents with more than one page, just hit the plus sign and keep scanning to create a multi-page PDF. When you’re satisfied, the app saves your scan to Google Drive as a searchable PDF.
Then, you can manage all of your PDF documents inside Google Drive, uploading other scans you might have from other apps. Google lets you search across all of them for any text contained in the documents using its OCR (optical character recognition) power.