ThinkFree Office - The office productivity suite for on-the-go featuring online collaboration and the best round-trip...
Dialog Messenger - handy and feature-rich enterprise multi-device messenger available for server or cloud – Slack-like, but not Slack-limited
LibreOffice - Free office suite, open source, and compatible with .doc, .docx, .xls, .xlsx, .ppt, .pptx files. Updated regularly – download for free. Originally based on OpenOffice.org.
Ripcord - A desktop chat client for Discord and Slack
Google Sheets - Synchronizing, online-based word processor, part of Google Drive.
Ziggs - Smoothly Share Content Between Devices!