Google Talk
Call or send instant messages. Google Talk has been replaced by Google Hangouts as an add-on for the Chrome browser, but it's still available here for download.
Telegram is a messaging app with a focus on security and speed. Messages are heavily encrypted and can self-destruct. You can access your messages from multiple devices.
WhatsApp for PC is a cross-platform mobile messaging app which allows you to exchange messages without having to pay for SMS.
Zoom is an easy, reliable cloud platform for video and audio conferencing, chat, and webinars across mobile, desktop, and room systems.
Mobile messenger app with free voice & video call over 3G/4G & Wi-Fi.
Send text messages, voice messages, videos, documents, pictures or group messages and make free phone calls over an end-to-end encrypted connection to keep your communication absolutely safe.
Share photos, videos, music, files, documents and more between all of your devices. File sharing from phone to PC, phone to phone, PC to phone, PC to tablet.
Lightweight, customizable mail client