[androidxen]

I'm wondering if there's a way for not just the pdf files to be automatically synced (via GDrive or Dropbox), but also the annotations as well?

[Zubersoft]

The next major update (which is currently being certified by Microsoft and will be available next week I'm guessing) is adding the ability to synchronize to a cloud folder. Performing this kind of sync will process all data, including annotations (although you can selectively choose what kind of data is synchronized if desired). 

Mike