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

* Supported file formats

– 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
– CSV
– MARKUP(MD/HTML/XHTML/XML/DTD/XSL/XSLT…)
– CODE(JAVA/CPP/PHP…)
– EBOOK(EPUB)
…

* Creatable file formats:
– PDF
– TXT
– HTML
…

* Editable file formats:
– TXT
– MARKUP(MD/HTML/XHTML/XML/DTD/XSL/XSLT…)
– CODE(JAVA/CPP/PHP…)
…

* Document Search
– Support all of the file formats except PDF format.
– PDF will be supported.

* Available cloud services

– Google Drive
– Microsoft One Drive
– Box