10 Cheap (Or Free) IPhone Apps For Travelers
All you need is a wifi hotspot to make Skype-to-Skype calls free from your iPhone. The rates for calls to mobiles and landlines (both national and international) are affordable. You can also keep track of who’s online to send and receive instant messages.
Skype offers both pay as you go credit plans or a subscription that offers unlimited calls to landlines and cell phones (in some countries).