Small and fast document viewing application for Open Document Format (OpenOffice, LibreOffice), OOXML (Microsoft Office) and other productivity document formats. It allows opening office productivity application documents, like text files, spreadsheets or presentations, located in the filesystem, e.g. on sd card, as well downloaded documents, files on Dropbox, Box, or documents files attached to an email.

Additional features
• zooming in and out of documents
• searching inside documents
• finding documents containing given words via a full text search across all text documents
• copying text from documents
• reading text documents (.odt, .sxw, .docx, .doc) aloud via Android's text-to-speech functionality
• printing documents via Google Cloud Print
• day/night mode (requires Android 4.0 or higher)

The following file formats are currently supported
• OpenOffice 2.x, 3.x, 4.x and LibreOffice Open Document formats: .odt (Writer), .ods (Calc), .odp (Impress)
• OpenOffice 1.x formats: .sxw (Writer), .sxc (Calc) (no support for embedded images)
• Microsoft Office 2007 formats: .docx (Word), .xlsx (Excel, only plain cell values), .pptx (Powerpoint)
• Microsoft Office 97 formats: .doc (Word, plain text extraction only), .xls (Excel, only plain cell values)
• PDF (experimenal on Android 4.4 and lower, needs to be activated in the app settings)
• ePub books
• Other formats: RTF, HTML, .txt (plain text), .csv (comma-separated values), .tsv (tab-separated values)

Please note that some restrictions apply for viewing documents
Displaying the documents is done via a conversion to HTML, which is why the document will look differently than if viewed with a desktop office productivity application
• Large spreadsheet documents may take some time to open, or sometimes not open at all
• When displaying images, only those images will be shown where the image format is supported by the Android browser
• Password-protected Microsoft Office docs cannot be opened

https://play.google.com/store/apps/details?id=de.joergjahnke.documentviewer.android.full&hl=en