I run VASSAL on my MacBook http://www.vassalengine.org/ It needs Java so it won't run on an iOS device. VASSAL had hundreds of game modules - especially wargames. You can play solo or online against another human. There is no AI however. Please make sure at least one of the players owns a copy of the game. There are a few game modules at VASSAL that do not have a cardboard equivalent; those can usually be played with no 'ownership' type restrictions. AH and GMT are especially well represented in the module offerings.