ooVoo’s is a simple cross platform voice and video calling app available for major mobile platforms and desktop OS. Similar to other apps, ooVoo sends messages, makes voice and videos. Like Skype, ooVoo permits you to call landline numbers through ooVoo credits. It also integrates with Facebook, so you can chat with friends from the social network. The best part about the app is that it makes group video calls with up to 12 people simultaneously.