Most of the time when boardgame apps are done on mobile, there is an announcement that it’s coming.
Recently, Friday dropped onto the App Store with no warning whatsoever (and a couple of key bugs too, which have now been fixed). This Friedmann Friese classic has you in the role of Robinson Crusoe, stranded on a tropical island and trying to get off (or at least survive your stay on the island). You must also survive two attacks by pirates at the end of the game. If you do all that, you win!
Friday is a solo deck-building game where you are trying to simultaneously defeat hazards to gain new cards as well as fail at defeating them so that you can get rid of really bad cards.
This tug-of-war is actually quite fun, though it can be frustrating at times.