coding, designing & hosting of a mobile phone app

just for professionals: coding, designing & hosting (just short term) a mobile phone app according to the below inputs (& further inputs during the project) coding an app, where everyone can post a specific order on a google map. when ordering, some parameters as "subject of the order", "delivery time", "delivery location" (on google map), "picture" must / can be entered. when ordered, anyone within a specifyable distance (not by the user, has to be done by a administrator) can make offers. an offer includes "subject of the order", "price", "delivery time as soon as accepted", "picture". the user who placed the order can review all offers on his order and select the best one (similar to freelancer, just for orders closeby which have to be delivered fast). When the order is accepted, both users must have the ability to text (& send pictures) to each other if something has to be specified. to close the order, both parties have to rate each other (stars) until it disappears from their interfaces. each user (orderers & suppliers) have an own profile page, where the ratings are visible as well as they can upload a profile picture. a further challenge on this is, that professional suppliers (for example a pizza delivery service) can reply with just a few clicks within an individual interface (their own price list, which they can easyly input by themselves) to the orders. another challenge is, that the administrator (me) can adjust / monitor / ... all parameters with an interface which needs no coding knowledge. designing a smart, easy, intuitive design is asked, with as few clicks to order & offer as possible. furthermore, as few information should be on the screen as really needed. in the first stage, it could look technically, until all design matters are specified based on the technical app. hosting in the first stage, development is just for android, but must also be able to adapt for iphone. for testing reasons, the app should be hosted by you for up to 100 users. this job needs a lot of interactions with me as i have some rough and some more specified ideas on the app. therefore a step-by-step approach would be done afterwards. however, please offer for the total project. thanks for reading & offering!