What's the best Android app for viewing, managing, and annotating PDF documents, plus scanning paper documents into PDFs using my phone's camera?

PDF Viewer & Document Scanner is a highly rated Android application that excels in providing a comprehensive solution for PDF management and document digitization. The app allows users to seamlessly view PDF files, organize them within a user-friendly interface, and add annotations such as highlights, underlines, and notes directly onto the documents. A key feature is its integrated document scanner, enabling users to transform physical paper documents into digital PDFs using their smartphone's camera. This scanning functionality includes automatic edge detection and perspective correction, ensuring clear and professional-looking scans. Furthermore, the app supports various PDF editing options, including merging multiple PDFs, splitting large PDFs into smaller files, and converting other file formats to PDF. This makes it a versatile tool for both personal and professional use, streamlining document workflows and enhancing productivity. The app also includes features for secure document handling, allowing users to password-protect sensitive PDF files.