3. Viber

Viber is an instant messaging and VoIP service providing app that was launched for iPhone on December 2, 2010 to compete with Skype. Presently, the software is available for Mac OS, Android, BlackBerry OS, iOS, Series 40, Symbian, Windows Phone, and Microsoft Windows.

Viber works on both 3G/4G and Wi-Fi networks. It first requires installation on a phone in order to work on a desktop operating system setting and then one can send and receive text, picture and video messaging across the world along with voice calling.

Viber offers all their features for completely free of cost with no subscriptions and no additional purchases required. Viber has over 100 million monthly active users from its 280 million global registered users.

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