Early 2010, the company I was working for as a software engineer went bankrupt. Good part of it is that we were notified 6 months before the decided shutdown day, and we were encouraged to stay for 6 months in case somebody would need us. During this time, my job tasks decreased drastically, so I had to find something to keep myself busy at work. That's when I started doing Android development.
Battery life on my HTC Hero back then was pretty bad, and I tried some app from the Market that aimed at improving this. It was good to believe that improving battery life could be achieved by software, but the app I tried back then didn't worked very well and so I started making my own.
A couple of month later, first version of Green Power was up and running. I orginally made it for myself and never intended to share it on the Android Market. But for the fun of it, I published Green Power, and looking at the download curve soon realized that people were in the need of such an app.
Since then, I've added many features to the original version, corrected many bugs, made a premium version. Currently I've reached over 500.000 downloads and I'm still working to improve the app and add new features as I get smart suggestions from the users.
When not working on Green Power, I do have a real job and the rest of my time is taken by my family.
Gaël Pouzerate (Google+)