N Docs allow you view documents on Android. No internet connection is required.

Support file types:
• Microsoft Word (DOC/DOCX, don't support password protected file)
• Microsoft Excel (XLS/XLSX, don't support password protected file)
• Microsoft PowerPoint (PPT/PPTX, don't support password protected file)
• Open/Libre Writer (ODT, Open with thirdparty app)
• Open/Libre Calc (ODS, Open with thirdparty app)
• Open/Libre Impress (ODP, Open with thirdparty app)
• Hancom Hanword (Open with thirdparty app)
• Hancom Hancell (Open with thirdparty app)
• Hancom Hanshow (Open with thirdparty app)
• Portable Document Format (PDF, support password protected file)
• RTF
• TXT
• MARKUP(MD/HTML/XHTML/XML/DTD/XSL/XSLT)
• CODE(JAVA/CPP/PHP)
• EBOOK(EPUB)

Create file types:
• PDF
• TXT
• HTML

Edit file types:
• TXT
• MARKUP(MD/HTML/XHTML/XML/DTD/XSL/XSLT)
• CODE(JAVA/CPP/PHP)

Document Search:
• Support all of file types, except PDF.
• PDF will be supported.

Storage services:
• Google Drive
• Microsoft One Drive
• Box


https://www.anonymz.com/?https://play.google.com/store/apps/details?id=net.sjava.docs&hl=en