Due to transition of App Inventor to MIT, App Inventor was shut down and will be back up sometime first quarter of this year. At this time, I have an my own instance of App Inventor running and can add couple additional people to access my instance. If you are interested, follow up this link and post your request here: https://groups.google.com/d/msg/apptomarket/9NOvj640dy8/3dfPPGa2K7MJ
-Hossein
