Known communication application Viber will release new features for secret chat later this week. This update is an extension of the idea of secret messages Viber introduced recently. With them, users can set a limit on how long to be visible a message or picture. If it sounds like Snapchat, it's true. The difference with the new secret chat is that whole conversation will be able to "self-destruct" a preset whether the exchange of messages between two users or group chats. Alternatively you to "lock" chat with a PIN number.