Viber

About

Viber offers free and secure calls and messages to anyone, anywhere, so you can keep your conversations going no matter where you are. You can make high-quality voice and video calls, start group chats, and like or reply to messages in those chats. You can also start a group video or voice call instantly, and express yourself with endless stickers and GIFs.

Chats stay 100% synced between mobile and desktop, including one-tap transfer of calls. Viber also offers Communities, where you can take part in conversations on any topic you're passionate about. The company says its mission is to protect your privacy so you never have to think twice about what you can or can't share.