Annotations are going to be a problem, because I don't have access to information about how annotations are stored in forScore. It's a proprietary format (MobileSheets does this as well), so it won't be easy to unravel. I haven't had time to spend on this yet, but I don't have a sense yet for whether it will be possible to convert the annotation data or not. If you can export your annotations from forScore into the PDFs themselves, then you can manage those annotations in MobileSheets by enabling the "Allow editing of embedded PDF annotations" option in the annotations editor. Some of the functionality is unavailable when working with embedded PDF annotations though (as the PDF specification is more limited in what it supports). This all assumes that forScore is writing out the annotations as PDF annotations and not just permanently writing them into the page content stream (i.e. the page image itself).
Mike
Mike