Zeplin - Collaboration app for UI designers & frontend developers
Misakey - Send encrypted documents & messages to anyone
Mightytext - Send & Receive SMS Text Messages from your computer. Sync'd with your Android #
Wire - Private & Secure Messenger
ActiveWords - Auto correct on steroids
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.