Update Answer (after wwdc 2016):
IOS apps will require secure HTTPS connections by the end of 2016
App Transport Security, or ATS, is a feature that Apple introduced in iOS 9. When ATS is enabled, it forces an app to connect to web services over an HTTPS connection rather than non secure HTTP.
However, developers can still switch ATS off and allow their apps to send data over an HTTP connection as mentioned in above answers. At the end of 2016, Apple will make ATS mandatory for all developers who hope to submit their apps to the App Store. link