Corona SDK is a framework primarily used for making games, and it's quite popular among young people just learning how to code. It's perfect for after-school clubs, or perhaps a formal class in preparation for high school AP Computer Science. I think even motivated junior high students would get a lot out of it. Here are five reasons I think schools should teach it:
If you're a teacher considering Corona, I recommend you check out books by Dr. Brian Burton. If you order them from his site, you'll receive several updates a year for free. He currently has three books:
Of course these opinions are mine alone, and not necessarily those of Microsoft.