The official iOS Skype apps have been updated with two-way HD video calls and lockscreen chat notifications, which means now you can make a complete HD video call where both interlocutors enjoy the same high quality of the video. The Skype for iPhone and Skype for iPad apps were updated with support for HD video calls on the iPhone 5 and the fourth-generation iPad back in August. Now, both apps have been updated with support for two-way HD video calls on the iPhone 5s, iPad Air and the iPad mini with Retina display.
Also, both apps have been improved so that push notifications for chat messages are now supported even when Skype is closed. Skype chat messages are now synced much faster across devices. Follow the links from below to download the official Skype app for iPhone and the one for iPad.
Source: iPhoneforums, Skype for iPad on iTunes