Skype is the most popular app for voice and video calling.In the mobile market, Skype has since long been dethroned by Whats App and Viber, but it still remains the most prominent tool for free communication on desktop computers.More » Another way to video chat on a computer is with oo Voo, which lets you connect with up to 12 people at once.As with Skype, you can make phone calls to non-oo Voo users (like landlines) if you want to pay a fee.
You'll be told of any plugin you may be required to download to make it work.
Use the Facebook Help Center if you need help using Facebook's video chat feature through or the mobile Messenger app.
More » on Apple's operating system and devices, and only with other Facetime users.
However, if you do have a Mac, i Phone, or i Pod touch, make video or audio calls from the device almost in the exact same way you would make a regular phone call.
Similar to Google Hangouts, Facetime lets you search through your phone's contacts to find someone to call.