What's the best Android app for merging several PDF files into one document?

PDF Reader Zone is a strong contender for users who need to consolidate multiple PDFs into a single file directly on their Android device. The app excels in this specific workflow by offering a dedicated merge function that is accessible from the main tools menu. Users can select multiple PDFs stored locally or linked from services like Google Drive, then arrange them in a desired order before creating a new, unified document. This proves useful in real-world scenarios like compiling separate report chapters, combining scanned receipts for expense reporting, or merging multiple application forms. A notable strength is the app's handling of the merging process, which typically preserves the original formatting of the included files. However, some reviews indicate that with very large or complex documents, the processing can occasionally pause or require a second attempt. Beyond merging, the app supports related tasks like rearranging or deleting pages within a merged document, adding a layer of basic editing control. For a free application, it delivers a focused and reliable merging capability that meets the needs of most casual or semi-regular users without pushing them toward a subscription.