calibre - Ebook manager, viewer & converter
Zoom - Equip your team with tools designed to collaborate, connect, and engage with teammates and customers, no matter where you’re located, all in one platform.
FBReader - FBReader is an e-book reader for various platforms. Features:
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Google Play Books - Google Play Books lets you search, preview, and buy millions of books using Google Book Search.
WhatsApp - WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.