2 Viber
Viber lets users securely call and message other users for free. They can send stickers and and voice messages, participate in group calls, send files securely, and make video calls. If users plan on messaging multiple other users Viber has their back. With up to 250 participants in a chat group, virtually anyone can join the conversation.
Unfortunately, Viber doesn’t appear to offer group calling at this time, but it does let users send video messages. While this might seem like a step backward, because Viber offers such large chat groups, it may still be a great option for many businesses or groups that need to communicate with a very large audience.