* LibreOffice - Document Viewer is an office reader application support you to view documents types like Word (.doc, .docx), Excel (xls, xlsx), PowerPoint (ppt, pptx), PDF reader.

* Book reader : fb2, epub, mobi, rtf, pdf, djvu

* LibreOffice - OpenOffice - Open Document Viewer support ODT viewer and ODP, ODS viewer, LibreOffice Viewer, Epub reader