Spotify has put its Windows phone app into maintenance mode, a post on the company's support website has revealed. The news, discovered by MSPoweruser effectively kills the Spotify service for Windows phone users. In itself it's neither surprising nor an unreasonable thing for Spotify to do. Of the streaming service's one hundred million users how many do you think are on Windows phones? Not as many as a year ago I'll wager. Some of that will be down to a preference for Groove Music, but mostly it's down to the rate at which users are leaving the platform that Microsoft abandoned.The only thing to wonder about now is how long before the remaining big name applications abandon the platform.