Team Ansca (Gilbert Guerrero and Chia Hwu) made an app with the Corona SDK in 6 hours of actual development time at iOSDevCamp 2010. The idea for DIY Buddy came about because Gilbert has been working on DIY projects at home and wanted a way to easily annotate photos of his projects.
The app allows you to take a photo with your iPhone, add lines for measurements and text. You can also save the annotated image to the iPhone Camera Roll and email from your phone. On the iPad, you can annotate photos in your Photo Library, save the image and email from an email program. We think this is a useful tool for anyone doing construction projects, home decorating, and Burning Man art collaborations.
The entire app was written by Gilbert, who did not have a single line of code written until Friday at 9 pm. He had a working prototype on our iPhone and iPads by noon on Saturday that would draw basic lines and rotate a photo. I (Chia) provided marketing and moral support only, she did not code or create any graphics. By 1 pm Sunday we had an useable app that we showed to the crowd at iOS Dev Camp on both devices.
If you want to see how it works, we made the source code and assets freely available on GitHub.