I'm always partial to a true programming language, but for that age it might be too heavy. Kodu was specifically made to introduce programming to children. http://research.microsoft.com/en-us/projects/kodu/ I remember a Google Android based environment with a similar goal, but I couldn't find a link...

What ages the ages and are you specifically looking for a "No Coding Required" type environment? I'm only asking the ages, because I could recommend some more advanced tools if they are older.