Skype is available for all platforms and is very easy to use.
The app offers HD quality voice/video and is often argued to be the when it comes to both visual and sound quality.
Otherwise, oo Voo to oo Voo video and audio calls are completely free. For example, oo Voo lets you call a Mac computer from a Windows computer, or an Android phone from an i OS phone.
Once you're all setup, you can (almost) instantly connect with family, friends, co-workers, or anyone else who is using the same app.More » on Apple's operating system and devices, and only to other Facetime users.However, if you do have a Mac, i Phone, or i Pod touch, you can easily make video or audio calls from the device, almost in the exact same way you would make a regular phone call.Viber lets you turn the video off whenever you like, mute the call, or even transfer the call.It works so much like a regular phone that it should be one of the easier apps to use from this list. You can download the app on other devices like Android and i OS, but those devices can only use the text and voice calling features.It grabs hold of your webcam and microphone through the Google Hangouts website and delivers HD transmission of both right through the browser.