App Inventor

Chapter 11. Broadcast Hub

FrontlineSMS (http://www.frontlinesms.com) is a software tool used in developing countries to monitor elections, broadcast weather changes, and connect people who don’t have access to the Web but do have phones and mobile connectivity. It is the brainchild of Ken Banks, who has probably done more to help people using mobile technology than any other human alive.

FrontlineSMS runs on a computer with a phone plugged into it. The computer and plugged-in phone serve as a hub for SMS (short message service) text communication within a group. People who don’t have Internet access can send in a special code to join the group, after which they receive broadcast messages from the hub. For places with no Internet access, the broadcast hub can serve as a vital connection to the outside world.

With App Inventor, you can create your own SMS-processing app. The cool thing is that the people who use your app don’t need to have an Android phone. Your app will run on an Android device, but your app users can interface with it through SMS using any phone, smart or not so smart. Your app will still have a graphical user interface (GUI) as well, but that GUI will be reserved for the administrator who monitors the activity via the Android app you’re about to build.

In this chapter, you’ll create a hub that works similarly to FrontlineSMS but runs on an Android phone. Having the ...