We both have iPhones and think they are great. I just upgraded to the 5S and hers will be here next month (She had to have a gold one). I use Gmail calendar. I have also setup a Gmail account for the DW. I set us each up our own calendar. Both iPhones sync with Gmail from the iPhone as you make changes on the iPhone or via the PC. I have access to her calendar and she has access to mine. Both calendars show up on each others iPhone. You could setup a single shared calendar that both of you update from your phones.