Viber (Android, IOS, Windows Phone, Blackberry):
Here’s an app to keep in touch with your friends, loved ones and travel companions. It allows you to call or text national or international Viber users for free. On viber, you can share pictures, videos instantly and if you’re adventuring in a group, you can keep track of all your friends through Viber’s group and location sharing features. Not everyone in your group has Viber? “Viber Out” is a new feature that lets you call landlines and non-Viber users at low rates, thus helping you connect across the globe.