Looking to hire a Mobile App Developer/Designer for iOS and Android

Hello I am looking to hire a team or individual for completely developing & designing Mobile App in iOS and Android, Apps that work perfectly on all iPhones and iPads on all Android Mobile Phones and Tablets Minimum screen resolution for a device that should run this app perfectly is 3inches Project details will be discussed with those that are short listed, please share some of your best App works till date and their costing, also please provide details of the technology that you intend to use to develop this app and what will be the running cost of these apps App needs to be able to handle large number of concurrent users I am also looking to hire a website developer that can develop a background service so that the App can interact with a web-server Some of the features required in the mobile App ->App needs to accept Online Payment from PayUMoney Payment Gateway and send Payment Receipt Confirmation notification to the web-server ->App needs to use MAP service for real-time location services --->Like saving a location for future use etc --->Finding service in a particular location ->There will be 2 modes of App --->1 is for Customers --->2 is for Service Providers Customers should be able to download App from respective App Stores and register themselves using their Mobile Number and Password Customers should be able to view a list of Service Providers based on location, should be able to hire a service provider After hiring Customer should have an option to Call or Text his Service Provider Customer should be able to use MAP area to drop a pin, this pin location should then be sent to the web-server Map Area should also have option to type in an address like how it is with Google Maps Service Provider should be able to share a location with his Customer