There are numerous paper to PDF scanners on App Store, notably Scanner Pro, Adobe Scan, iScanner, Tiny Scanner, Evernote Scannable, etc. Other apps like Dropbox or Google Drive, can also help us scan documents using our devices camera. With the release of iOS 13, you can now directly scan a document right from the stock Files app. No third-party scanner app required.
Firstly place anything you want to scan, books, magazines, newspapers, receipts, on a flat surface. Open the Files app on your iPhone iPad. Long press on the blank area to pop-up the shortcuts bar where you can see New Folder, Scan Documents and Info. Tap the “Scan Documents” button from the menu bar.
Position the document in view. When the document is perfectly placed, it will be scanned automatically. If not, tap the circular capture button on the phone screen bottom to take the shot manually. Then drag near corners to adjust and select the area you want to keep. Choose Retake if you don’t like the current scan and do it again. Choose Keep Scan to scan the next page. Repeat the process to scan additional pages until you finish scanning all pages or documents. Tap Save button, the scanned pages will be saved into a PDF file in the current folder in Files app.
Other then scan and save PDF files in local folders in Files app, you can also access your iCloud Drive from Files app, then scan documents and place scans directly into your iCloud account.
You can also copy or move your scans between local storage and iCloud using the Files app.