How I Use It
I actually began using Light-bot with my 3 year old son at home. I really want to introduce him to programming concepts early, and this was a great way to start. As I mentioned, the "Procedures" challenges were a bit too difficult for him to do on his own, but he still enjoyed going through them with my help.
At school, I introduced this to my students in my intro to programming class (9th - 10th grade). I only showed it to them for a day and encouraged them to continue playing in their free time. They didn't continue playing very much after a couple of days, but they still seemed to like it. It helped to communicate the idea that programming is just giving a machine instructions to make it do what you want. One potentially promising feature that I haven't yet tried is the Light-bot competitions that will allow students to compete with and compare their scores to those from students from other schools. Additionally, the school challenges are supposed to offer new levels.
Light-bot is a great way to get kids to start thinking logically. The app is basically like a series of puzzles that are very simple at the beginning, but get more and more complex as you progress from one level to the next. At each level, your objective is to move the robot around the squares to light one or more lights. One of the things I like the most is that there is often more than one way to complete each level. This is just like programming, as two programmers will often write code in slightly different ways to achieve the same goal. The game gives more stars for writing code more efficiently, which is good for getting students to think about solving problems efficiently.
The app is great for people of all ages, but pre-schoolers and kindergartners will likely find it too difficult after the first couple of levels in the Basic section (after basic challenges, players move onto procedures). In both the paid version and the "lite" version, if they offered more basic level challenges, it might be more engaging for younger kids. The paid app does offer levels challenging enough for more advanced students. In fact, I still haven't finished the last two levels myself.