I've been using Exogear Strategies app on my tablet for some time to play Heroes 3 (which it does very well). The app was updated this week and now supports PG2 (using the same control scheme as Heroes 3, so one purchase covers both). I started the 1938 campaign on my way to work this morning and it plays very well. The only thing I haven't figured out is how to preview the outcome of an encounter.

I've owned the game since its original release and always wished for a portable version,

Here is the link to the app on the play store:

https://play.google.com/store/apps/details?id=com.eltechs.es