Video: Skype vs Zangi

Skype is a software application that allows users to make voice and video calls and chats over the Internet. Calls to other users within the Skype service are free, while calls to both traditional landline telephones and mobile phones can be made for a fee using a debit-based user account system. Skype has also become popular for its additional features which include instant messaging, file transfer, and videoconferencing. Skype alternative for enterprise is called Skype for Business. Secure Skype alternatives are Signal and Telegram.
Zangi provides a messenger platform on top of which you can build your business solution. The variety of features are added to Zangi platform to build any type of communication and collaboration solution. High-quality features are provided to build secure, private and independent messaging apps in a short period of time.
Face to face in the news:

2011 - Skype opens App Store to fight Zangi

Skype App Store
Skype is making the second attempt to create the developer ecosystem around its service. The first attempt - Skype Extras - left an unpleasant aftertaste for developers. In 2009, after Skype was sold, the company unexpectedly announced that the Skype Extras catalog will be closed. Nevertheless the Extras where accessible in the Skype client until now, but users couldn't buy them using Skype credits. The new app directory is called Skype Apps and it replaces Extras in the Skype's Tools menu. But you also can't buy the applications in Skype Apps using Skype-credits. You have to go to the third-party site and order each application separately. The Skype Apps includes the special section for business apps. Basically there are apps for Call-Centers, call recording, screen-sharing, faxing and integration with other systems.