A few folks have been noticing that the MixRadio app for Windows 8.1 appears to have been removed from the Windows Store. This is absolutely the case, but before any "sky is falling" reactions have chance to manifest, it's not permanent. The app will return, and it's down to payments and accounts that it had to be removed at all.
"@Ricker666 afraid so, it uses Nokia account and payment services that are being closed next month. We'll be back later in the year."
It's not at all surprising, since the mobile app has also had to start going through some changes with regards payments and the premium service. After we met with the MixRadio team at Mobile World Congress we were able to confirm continued development for Windows and Windows Phone with an exciting future for the company under its new owners.
So, there we have it. It's gone for a while, but it'll definitely be back.