Telegram is a free cloud-based instant messaging platform.

Flock is a communication app for teams. Packed with tons of productivity features, Flock drives efficiency and boosts speed of execution.

Threema is an encrypted instant messaging application for iOS, Android and Windows Phone.

Sicher is a freeware instant messaging application for iOS, Android, and Windows Phone. Sicher allows users to exchange end-to-end encrypted text messages, me…