Chemistry Pre-Level 1 is a tough app to review.
On the one hand, I think the idea of a chemistry app for first-graders is fantastic and CPL1 does a good job of explaining the basic concepts on that level. The illustrations are comical and the sections are short and quick.
On the other hand, it's $9.99, very expensive for an iOS educational app.
On the next hand, the app obviously isn't something a six-year old is going to pick up and read through themselves and that's something important to me because one of my goals is to find apps that so blur the line between education and entertainment that my children choose to play educational apps in their free time, not just when their parents are "making them."
On the fourth (and final) hand, for a homeschooler or parent who does want to sit down and spend the time introducing chemistry to their child, it's great.
So, the rating of this app all depends on what you expect from it. I'm going with three stars to split the difference.
As a side note, I think apps specifically designed for homeschool use could dramatically increase their audience if they were to think a bit outside of the homeschool box. I plan to sit down and read this app to my first grader, but for a lot of kids that obviously isn't possible. Adding a voice track and a few sound effects, that could be turned off if unwanted, would make the app accessible to a lot more kids.