Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Freshservice - Freshservice: the one-stop cloud solution for all your IT management needs.
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.
Freshdesk - Freshdesk is a cloud-based customer support software that lets you support customers through traditional channels like phone and email, social channels like Facebook and Twitter, and your own branded community
Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.