DoubleTwist the media player for Android and iTunes alternative for Windows has been updated trying to fix the SD functionality after recent changes to SD card support in KitKat (see this post). The app now has support for sandboxed folders on KitKat SD-Card devices so media can now be stored on an SD card (with some limitations). The app also support Qualcomm AllPlay enabled speakers.
The app and Windows software can be used to move from iTunes and iOS as well as being an all in one media app for Android. doubleTwist is free and then there are in-app purchases for the pro version and radio streaming. You can find the app in the Google Player Store
♬ Support for WiFi speakers powered by Qualcomm AllPlay.
♬ Support for syncing media to the sandbox folder on KitKat SD-card devices (subject to limits and drawbacks imposed by Android, such as synced media being automatically deleted if you uninstall the app). If you are syncing with a Windows PC make sure to also update to the latest version of our Windows client.
♬ Removed support for importing pinned Play Music tracks per request from Mountain View. Sorry, root users 🙁