It's 3 for the moment: AirMail, Agenda, Notes. The last one is not cool or convenient IMHO, so I did not mention it. Anyway I provided a direct link to application store containing a full list of Planet Computers applications.
I am an owner of Gemini PDA, AirMail and Agenda app work fine for me, but according to reviews in the application store there are issues with devices produced not by Planet Computers. Pro1 will have more recent version of Android and different hardware so it's a high probability that we'll see issues on Pro1 and they would not be fixed ASAP.