The Windows Store Skype app for Windows 8.1 has been updated bringing back signing out options. With Skype so integrated into Windows 8 until now you couldn’t actual sign out of the app you could one be marked as Invisible which still allows messages to arrive but other uses can’t see your status.
With the update you can actually sign out of the app so you don’t get any notification at all. This is a feature that Microsoft took out some time ago and has been brought back due to user requests.
You can find the updated app in the Windows Store.
What’s new: – You can now sign out of Skype.