iPhone GPS Location Tracking App

I am seeking an iOS developer to assist with the development of a simple GPS Maps project where user GPS data will be stored on a web server at regular intervals and downloaded by other users ('friends') at intervals - a map will display where the users friends are located at any instance. I intend to use a simple MySQL/PHP framework to capture and store the GPS location data and to extract this data into xml files that are then downloaded by app users to extract and display pins on a map that show the user where his friends are located. An additional feature/requirement of this app is to enable the app user to define a point on the map ( a GPS way point) and a radius around the waypoint (witha a user defined radius length) that then defines are circular region around the waypoint. Users friends that are located inside the radius are detected and an alert is triggered within the app. Also, an basic online tool is required that enables the capture of GPS locations/radius (waypoint) that triggers a message to be sent to the user when they enter the radius. Each of the GPS waypoints will have multiple messages associated with them (approx 4 or 5) with each message being targeted to a different profiled group (Males under 25, for instance). This profile information is captured from the app user during registration. NOTE; PLEASE DO NOT PROVIDE A QUOTATION ON THIS PROJECT UNLESS YOU 100% UNDERSTAND WHAT IS WRITTEN ABOVE AND CAN 100% GUARANTEE THAT YOU CAN DELIVER. THIS PROJECT WAS AWARDED TO ANOTHER COMPANY LAST MONTH BUT THEY FAILED TO DELIVER! This is a basic breakdown of what I am looking for - a full brief will be supplied to winning contractor.