It hasn't happened yet, and there has been more than enough time, so I'd say, "doubtful" of Tower coming to Apple. The one glimmer of hope is now that Solo app is available for Apple devices...just perhaps they might recognize the value of doing this as more people ask for it. But then again, there is APM Planner versus Mission Planner. Little effort put into making APM Planner the equal of MP, so this again makes me think that it is unlikely that Apple will be getting a fair shake anytime in the foreseeable future. Sure hope I'm wrong, but no one at 3DR, to the best of my understanding, has yet made any move to correct my perceptions.
These issues have forced me to hang onto a Windows laptop for the MP and I have to borrow my wife's Android phone for Tower. Yeah...any husband tell me how well your wife stands letting you borrow HER things for YOUR hobbies...uh, huh, that works out well.