build a wordpress plugin

I need to build a wordpress plugin where I can create some data that will be readed by wordpress api (json) to be displayed on a mobile app. There's 4 main contents: - Leadership - Elders - Departments - The church - Calendar The leaders, and Elders are just people. I need some basic information about then. The wireframe is jsut to show the conecpt. The interface can be different. The wireframe are the same for Leader and Elder The DEPARTMENTS has one Leader and one Elder When creating/updating the department, the user must select for each department one Leader and one Elder already created (can be blank) In the church, are just some itens with a rich Text. Nothing else And at last: The calendar. The user select a calendar, and manage all event of this calendar (create, edit, delete). You can use the google interface, if you wish. You must use the Google Api to connect to one account and get all calendars. Can't use Oauth. The autuentication KEY will be saved in the plugin config or even in the code. This are just the basic ideia. If we make a deal. I will create a complete specification for the app The use of the Google Calendar isn't fully [login to view URL] you believe it's easy to create your own calendar component (thre's a lot template on web) you could create it. For each event I basically need these information: - Title (required) - Start date (required) - End date- Time (ex: from 08:00 - 10:00) - Description - Place - Notification (will notify this event? how many days/hours before) Just one more optionSee what's better