Corona Project Manager is a must have if you are going to be a serious Corona developer.  It keeps your projects organized, allows you to import assets from other projects, keep a code library, view assets, open them in outside editors, and launch the simulator.  It has built-in features to help you configure your build.settings and config.lua files with just a few clicks.

I tried doing some work without CPM.  It made me really appreciate what a great development tool CPM is and how essential it has become to my app development routine.

Vendor: J.A. Whye

Cost: $75

Website: http://coronaprojectmanager.com