Microsoft had been offering a touch-friendly 'modern' Skype app on Windows 8.1 Store and a separate traditional desktop app for Windows 7 and Windows 8.1 PC. Microsoft has decided to kill the touch friendly version in favor of the traditional PC app. Users of the touch-freindly version of Skype will be pushed towards the desktop version starting July 7th.
Modern version of Skype
Desktop version of Skype