Unless I'm mistaken, Crestron Mobile (iPhone) and Crestron Mobile G (iPad) would only load a project that was designed for their respective device.? If you want to use only one instance for both devices then you would probably need to install Crestron Mobile on the iPad instead of Crestron Mobile G.
If you still can't get it to work then I'd recommend posting some screenshots of the symbol configuration in Simpl, the Ethernet settings of the processor, and the configuration in the app.? Otherwise people here can only guess at what the issue is.
The "platform not supported" error will also be triggered if the web port is incorrect.? Are you trying to connect from the LAN or WAN?? If you aren't on the WAN then I would make sure http port of your processor hasn't been changed.? If you are on the WAN then I would make sure the port isn't being blocked by your ISP.
Steve McNally