Hire a Mobile App Developer

I would like an app for both android and apple platforms within the genre of social media. I would like it designed to enable any user to put forward a task (which is displayed in a task list. The list should also show a user's identity by photo and brief background next to the task they uploaded). The task should be visible to all other users (within their specific, assigned geographic area based on where the user him/herself lives) and any other user (again only within their specific, assigned geographic area)can accept that task. Once the task is completed the app should show a tick next to the task and indicate the date and time it was completed (based on when the user notified the app that the task was completed. The app should keep track of which user has completed a task and it should give points to each user for completing a task and keep track of the amount of points each user has. There should be an integrated google map on the app which shows the location of where the task should be completed/take place. Users should be able to upload a task either by text, uploading a video, photo or audio message for other users to see. There should also be a feature where as administrator of the app, I am able to upload videos which all users can see and I should be able to relay other information/documentation. Users should be able to communicate to each other to ask further questions about a task. The app should utilise mobile phone contacts to assist in creating a user database (like whatsapp...users are identified by their mobile number and photo). The app should be both child and adult friendly and have an easy to use UI naturally.