Project Planner iPhone

Is it possible to share or update projects between all 2 iPhones by email? I saw exporting and importing features in iTunes but it doesn't clearly explain if I can do what I want. Here is the situation, I have two iPhones: mine and my wife's. We have some projects we will be doing together in the future and it will be great if I can use an app to create these projects, tasks, timeline/deadline for each task, assigning responsible resources for the tasks, etc. and then email the project to my wife. Then she can just open the email and updating the changes I made on my iPhone/iPad to the same projects in her iPhone.