Read up about Telegram Messenger, a solid Whatsapp alternative (link)
Whatsapp was swallowed by Facebook in exchange for a cool $19B. To keep it exciting and in the news, the CEO, Jan Koum, announced that they will be bringing voice services to market. Sure you can send voice notes today but they want to bring actual voice calling functionality to their users.
Is this something that excites you? Do you really need another VOIP client? It is a platform with more than 400M users so adoption will be incredible. It is important to note that this functionality (along with video chatting) already exists in the current Blackberry BBM client (IOS, Android and Blackberrry 10).