This is the pro key for the Chess PGN Master http://play.google.com/store/apps/details?id=com.kalab.pgnviewer
It removes the restrictions of the free version and adds an edit mode which allows you to:
* try out analyzed lines
* edit annotations
* promote variations
* delete moves and variations
YOU NEED TO HAVE BOTH APPLICATIONS INSTALLED, THE FREE VERSION AND THIS PRO KEY.
Original key icon by Stephen Hutchings https://github.com/stephenhutchings/typicons.font