Mobile messaging apps often used to deliver sensitive data or used for personal and corporate communications, so the data stored by the service provider should be encrypted end-to-end, which is not yet in the case of WhatsApp. WhatsApp acquisition may have had a negative impact on the reputation of the company, it seems many users are planning to switch the service and a few of them have already done it. There are a number of solutions available includes – Telegram, Surespot, Threema, TextSecure, RedPhone etc.
Source: https://thehackernews.com/2014/02/5-best-whatsapp-alternatives-with-end.html