Both iOS and Windows Phone 8.1 builds are still in review.
I am aware that there are still issues with Android audio, due to Android bugs. I have a certain idea how to fix them once and for all, but I am not sure yet whether it will work. I’ll let you know soon.
Windows 8.1 build is ready for submission as well, but I am waiting to see how Windows Phone 8.1 will fare first.