It’s not every day that students can earn money for turning in their homework early. But that’s what four Course VI undergradu­ates did, beating a deadline for Professor Hal Abelson’s class Building Mobile Applications to enter their project in Google’s Android Developer Challenge. The effort paid off in August, when Google named their entry one of the top 10 applications for its open-source mobile-phone operating system, Android–a distinction that came with a $300,000 check. The students’ application, Locale, allows a user to program his or her phone to change its settings automatically depending on its location. For example, a phone might be set to change its ring to vibrate at the office but play a pop song when the user is at a favorite hangout. Not only does Locale control a phone’s standard settings, but it can be extended to govern settings for other third-party applications as well.

The project got under way last spring when Clare Bayley ‘10, Carter Jernigan ‘08, Jasper Lin ‘08, and Christina Wright ‘08 signed up for Abelson’s class, which paired students with industry mentors such as Android’s Rich Miner. Working with Eric Carlson and Dave Mitchell of Connected Bits, a company in Nashua, NH, that develops mobile applications, the four wrapped up most of the work for their project a month early to meet the deadline for the Google contest. After advancing to the second round, they added Jennifer Shu ‘03, MEng ‘05, to the team and worked day and night through the summer to perfect the program. “We were having code-athons every single weekend,” Jernigan recalls. Lin adds, “Jenny would go to work, come home, then stay up all night working on Locale.”

Lin says that he thinks the team’s ­invention appealed to Google in part because it takes advantage of features that set Android apart from some competing systems, such as the ­ability to keep an application running in the background at all times. This ability is crucial to Locale’s design, since the software depends on constant awareness of a user’s location and situation. The students couldn’t have built the program for a device such as the Apple iPhone, which allows third-party applications to run only when the user deliberately accesses them.

Abelson notes that every team in his class of 25 students came up with working software. He offered the class again in the fall, this time allowing students to build applications for Nokia’s platform and Windows Mobile as well as for Android.