I was recently asked, “What does it take to get started with mobile app development using Corona SDK?” in one of my classes. Here is my response:

It will depend on your development goals. If your goal is to develop for iOS (iPhone & iPad), then you will eventually need xCode for submitting the app to the iTunes app store and deploying to test devices. If you wan to sell on Amazon, Google, or Barnes and Noble, all you need is Corona and to install the Java 6 SDK (32 bit version at the time of this writing).

All stores require a developer’s account subscription:
Apple: $99/year
Amazon: $25/year
Google: $25/lifetime (I think)
B&N: Not sure, I don’t publish my apps or books on their stores because their sales percentage is not in-line with the industry.

BUT, you don’t need to purchase your developers account until you are actually ready to start selling your app! You can use the Corona Simulator to handle 80% of your testing.  The only exception would be if you are using a native feature such as textfields or textboxes.

You can also use the trial version of Corona SDK until you are ready to publish to a store (again, a good idea as the license is good for 1 year).

For development, all you have to have to get started is Corona and some type of editor like textwrangler or textpad, or, my favorite, Corona Project Manager (there is a coupon in chapter 17 of the book that will save you $25).

Remember, if you want to develop for the Apple iTunes store, you must do the final build and deployment on an Apple machine.  To deploy and test on an iPhone or an iPad you will need xCode.  xCode makes testing easy with the their simulator (which does support the native fields, so you can test before deploying to a device) and the organizer, which makes it easy to deploy to your test devices.  You will also need Apple provisioning configured to deploy to a test device, which does require you to be a registered developer.