You may know LibreOffice from the desktop - the free and open source office suite (successor to OpenOffice) with over 200 million users worldwide. It's secure and respects your privacy not sharing your documents with anyone else. It's also available for Android in a simplified form to view documents in these formats:

• Open Document Format (odt ods odp odg)
• Microsoft Office 2007–365 (docx xlsx and pptx)
• Microsoft Office 97–2003 (doc xls and ppt)

LibreOffice Viewer also has experimental editing features which are not yet suited to production use. (Experimental mode can be enabled in the app settings.) The software is open source and made by a worldwide community so if you'd like to improve the experimental editing support please join us!

Feedback and bug reports are very welcome to help developers improve the quality of the application. You can report bugs and attach files here: https://bugs.documentfoundation.org

LibreOffice Viewer is built on the same technology as LibreOffice desktop for Windows macOS and Linux. LibreOffice Viewer is released under the Mozilla Public License v2. The software is backed by a dynamic community represented by The Document Foundation a not for profit entity based in Germany.

LibreOffice was based on OpenOffice.org (commonly known as OpenOffice). Full credits: https://www.libreoffice.org/about-us/credits