Here’s a link to a couple articles on the Corona web site about making apps to fit a wide range of screen sizes. Be sure to comments there’s a lot of good questions and answers there. The second articles takes the whole concept to a very elegant solution.
- http://www.coronalabs.com/blog/2012/12/04/the-ultimate-config-lua-file/
- http://coronalabs.com/blog/2013/09/10/modernizing-the-config-lua/