at least on the offline iOS version it seems if a white pawn is on f6 and a black g pawn advances two squares in front of it, it can't en passant
A white pawn on f6? Think about that for a minute.
To capture a black pawn en passant, a white pawn must be on the fifth (!) rank. This works as intended in the android Version.
Ah, ok, I wasn't thinking clearly, they have to end adjacent. I thought en passant could trigger whenever a pawn moves 2, and goes past another pawn.
#4
http://en.wikipedia.org/wiki/En_passantThis move was introduced to reduce the powerful effect of the pawn double-move.