PdfViewPager

Android widget that displays PDF documents — from app assets, SD card, or remote URLs — inside Activities or Fragments, with built-in pinch-zoom and panning gestures baked into the widget itself. Requires Android API 21+, since it's built directly on the platform's own `PdfRenderer` class rather than bundling a separate rendering engine like PDFium or pdf.js. A lightweight choice specifically because it leans on what Android already ships rather than adding a rendering dependency.