Recently I did a review of Instacast for Mac. One issue that hurt the app was the syncing issues between the Mac and iOS versions.
My colleague Michael pointed out a fix to me that has worked beautifully. It involves putting the following command into a browser on either the Mac or your iOS device of choice: ‘instacast3:///sync/reset’.
It brought up this screen on my Mac (I chose the “Keep content from the cloud” option)
I also did the same thing on my iPhone.
Though my review still stands since it is still an issue without this fix, hopefully this issue will be patched in a future update without having to use a workaround.