Skype lets you make free voice and video calls to other Skype users, and to call any regular phone line for reasonable rates. You can also chat online for free, and because it's so widely used, there are few people you can't communicate with for free using this service.
Contact integration: You can now import all of your contacts from Facebook and Microsoft, so you can keep them all collected in one place. And because so many people use Skype, it's likely you can message or call just about anyone you know right from the app.
Screen share: It's now possible to share your screen with other users during a Skype call. This is a great feature, whether you're making calls for business or personal purposes, and it worked well during testing.
Duplicate contacts: When you import your contacts from another account like Facebook, it will add everyone including people you already had listed as regular Skype contacts. Fortunately, the profiles imported from Facebook are labeled as such, but you still have to go through and manually remove any duplicates you don't want.
Skype has been around for a while, and although its call quality can be up and down at times depending on the quality of your connection, its ubiquity makes it the best option for free calls and chat. Rates for calls to regular phone numbers remain very reasonable as well, and the interface on this version is streamlined and intuitive.