[Update 10/16/2013: It now allows free spotify users to login and play tracks]
Since Spotify will not build a store app for Windows 8/8.1, I decided to develop my own app to listen to Spotify. It took a few months to reverse engineer Spotify APIs but finally it is working and stable. It has been on the Windows Store for over a week now and I have fixed many glaring glitches to make the experience smooth. Currently it only supports Spotify Premium/Unlimited users as Free accounts have to show spotify advertisements at regular interval and have many restrictions. If you have a Spotify Account and would like to try this on Windows 8 then head over to the Windows Store and download it. Here is the link to the description page and the download link is in the page. It is only available in select countries like US, Sweden, Germany, UK, Mexico etc. Feel free to report any glitches on this thread or at the spotlite website.
Your app is awesome, thanks a lot! I got one problem though: Playback often stops, telling me that my internet connection is too slow. Which certainly isn't the case. I never had that problem with my pc or my mobile phone and I'm always streaming the highest quality possible. Any idea?