Skype is a free instant messenger that allows you to connect to other users on Skype. It also allows chatting with normal telephones, as well as sending an SMS. The application does not need to use a direct connection to the Internet, because you only have to be connected to a WiFi network to be able to carry on a conversation.
System requirements: Windows Phone 7.5 or higher.
Skype 1.3.0.0 For Windows Phone Details
Developer: Microsoft Corporation
License: Freeware (free)
System:Windows Phone
File Size: 7 MB