Mobile Phone Remote Control

We support customers with their computers. That has now leaked into the cell phone arena. We are looking to develop an app that can remote control customer phones over the web, preferably in a webpage. Multiple people will log on to the webpage so we need to ensure the right phone is connected to the right screen. What I envision is the user installing the remote control app from the various market places, and giving us the key to connect to them, similar to gotomeeting for PC's. We would like this to work for Android and Iphone. Once finished we would like to add Windows 7 and Blackberry, but that will be a separate project.