It's good
Very, very useful tool
It is a good applicatin for who doing geology and chemistry
It's ok. The only issue is that the developer is a bit lazy with application descriptions so he uses the same description for the lite app as for the pro app which leads one to believe that it is the same thing just without adds but it it not, the lite version only has some of the models unlocked but with no indication that it is in the premium app or locked, you click on a crystal form only for nothing to appear which leaves you with the question. Is this content just missing or is it in the premium? Gees I don't know, perhaps I should lay off the premium version just in case it is just missing content. I believe the developer has spent a lot of time on the models and application but it's a bit like building a nice race car and giving it a poor paint job.