Mailspring - Mailspring is a mail client for Mac, Windows and Linux.
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.
The Bat - The Bat! is a secure desktop email client for Windows, designed to protect your correspondence against third-parties and to save your time.
Messenger Day by Facebook - Share your day in Messenger
Geary - Geary is an email application built for GNOME 3.
FastAd Market - Advertise on any social media platform using just one Ad. Make money when you share other Ads on the timeline.