How I Use It
I would use this in middle school to help students learn how protons, neutrons, and electrons build atoms and affect atomic number and atomic weight. This would be useful as a reinforcement activity; it could be a discovery activity with an addition (see "My Take"). This is probably best for middle school students; I could see high school chemistry students using this as review at the beginning of the year, but probably not much more.
The game that lets students build atoms and molecules is a nice learning tool. It could be better if it would display atomic number and atomic weight as the student adds protons and neutrons; that would allow students to discover the meanings of those terms for students. Also, the app starts with sound on and a narration from David Pogue. The audio can be turned off, but it should not come on at the start by default.