A full version app for Android, by Sharpened Productions.

File Viewer for Android is a free, fast, lightweight and easy-to-use app that lets you open files of many types, including PDFs, Microsoft Word documents, Excel spreadsheets, PowerPoint presentations, TIFF images, and more. The app supports almost all of the formats that you can open on your computer or laptop, so that you can view and manage these from your mobile device = formats such as Word and Excel files, PPT, TIFF, PDF, etc – even video and audio files such as 3GP, Matroska (.mkv), MPEG-4 (.mp4), Transport Stream(.ts), WebM, 3GA, AAC, AMR, and so much more. You can even view and manage raw camera files such as AVIF, Bitmap, DirectDraw Surface, GIF, HEIC or HEIF (for Android 9+ only) and ICO.