Build a mobile app along with back end in java.

To build a mobile app(both ios and android) including backend, design and app. Requirement with user flow, 1. Peter registers on the app. 2. Sync Peters phone book contacts to app contacts. 2. Peter sets his profile like below, a. Name: b. This will be a select field. This will be called a category. The values can be Baseball, Football, Tennis 3. Once profile is set, take Peter to the app contacts page and sort contacts by interests. For example, Under baseball- Tom, Harry and Pooja might show up, under Football- Jay, Rahul and Ash are shown. 4. Peter should be able to broadcast a message to all users or multiple users or a single user under a category. 5. The message will be in the following format, a. Category: Football b. Date & Time: 30/06/2016 at 9am c: Place: City grounds d. Message: Lets meet up for a game of football. Please call @ 9999999999. Kindly vote. 6. Peter sends this to all Contacts under category- Football. In this case, to Jay, Rahul and Ash. 7. In Peters phone, under a section called events this will be updated. In this case Peter is the moderator. 8. An event will always reside only on moderator phone. 8. Jay, Rahul and Ash will receive a notification about the event. 9. Jay, Rahul and Ash on clicking on the event, will see the below, a. Category: Football b. Date & Time: 30/06/2016 at 9am c: Place: City grounds d. Message from moderator: Lets meet up for a game of football. Please call @ 9999999999. Kindly vote. e. Voting options: Radio button 'Yes', Radio button 'No' 10. Jay and Ash click on 'Yes', Rahul clicks on 'No' 11. In this case, 2 people have opted in and 1 person has opted out. 12. On the moderator(Peter) app, under the event, people who said 'Yes' should be displayed along with a call button in front of them. 12. Under the event, moderator should be able to mark the event complete.