We all know about Skype, but have you heard of ooVoo? It's one of those apps that offers free video and voice calls. The app has more than 100 million users, so perhaps you are already one of them. If not, then now might be the right time to give it a go. If you are a tablet user then look for versions of the app for your tablet too – it supports Android tablets and iPad as well as iPod Touch, Windows and Mac.
As well as being able to make one-to-one voice and video calls you can have group conversations with up to twelve people and you can see four of them at a time on-screen. There's a free messaging element to the app too, so you can share text, picture and video messages.
OS: Android, iOS, Windows Phone