Back in August, programmer Patrick McConlogue offered Leo Grand a choice: $100, or 16 coding lessons. Grand -- homeless since 2011 after losing his job at insurance provider MetLife and being priced out of his home when a high-rise apartment block was built nearby -- didn't have to think for long. Coding lessons it was.

After furnishing Grand with a refurbished Chromebook and three books on coding, McConlogue met with him every weekday morning for an hour-long lesson.

Now, Grand has released his very first app: Trees for Cars, available for iOS and Android. The idea behind the app, Grand said, is to decrease the number of cars on the roads with a eye toward reducing CO2 emissions. Users sign up and specify whether they want to catch a ride or offer one, and the app will connect them with like-minded carpoolers nearby. The app will then track how much CO2 was saved by all the passengers.

Read it at CNET.