ScannerHD is the best free app that can turn your smartphone into a powerful scanner. The app lets you scan and save PDF documents to your phone, cloud, or shared drive. You can also convert your scanned documents to PDFs and save them to your device.

ScannerHD is a great tool for anyone who needs to scan documents or any other paper-based item. It is a handy tool for students, lawyers, business people, and even for office workers. It's very easy to use, so even if you have never used an app like this before, you will be able to quickly get up to speed.

The app also offers various editing and scanning options to make your PDF documents more professional. It has support for PDF and JPEG formats.