Science Glossary is an iPhone (and iPod touch) app that is basically a glossary of scientific terms and has some biographical data on famous scientists. However, a grievous error in one section calls in to doubt the entire project. Glossary data is also too simplistic and not educator driven.
One of the things I liked about this app was the glossary of scientific terms. I liked that more than just a collection of random facts because random facts, while seemingly impressive in some circles, don't really stem from a deep understanding. At least with a glossary, one can dig into specific area of knowledge.
The challenge for any app like this is to do more than look up information in a textbook and parrot it. Insight and information best comes from people who are experienced scientists and educators, not just catalogers.
One example is the short biography of Albert Einstein which got just about everything wrong:
Albert Einstein entry
Any working physicist or student of Albert Einstein knows that he received his Nobel prize in 1921 for explaining the Photoelectric Effect, not Relativity. (The problem was that his theory of relativity was controversial and not widely accepted until many years later.)
Worse, the thumbnail gives Einstein credit for being "deeply involved in the Manhattan Project," the project to build the first atomic bomb during WWII. There are many physicists who can take major credit for developing the first A-bomb: Robert Openheimer, Hans Bethe, Richard Feynman, Enrico Fermi, Edward Teller, and many others. Einstein's contribution was his original letter to president Franklin D. Roosevelt alerting him to the dangers and opportunities for the U.S. Yet Einstein was deemed a pacifist and denied a security clearance to work on the Manhattan project.
So, the app got that part very wrong, and it soured me on the credibility of the entire app.
Another example is the section on refraction. This glossary excerpt provides a simple, almost meaningless section of text which provides no insight whatsoever.
Less than illuminating definition of Refraction
Anyone who's played with a glass of water and a pencil or lenses knows that glass refracts light. But explaining what refraction is, in terms of its effects, rather than its cause, dispersion in materials (index of refraction dependent on wavelength), is just not satisfactory. I found the same level of detail wanting in the description of "supercomputer."
While most of the glossary entries are accurate at face value, my reaction was that data entries were simply lifted from sources without insight or depth and are therefore deceptively simpleminded.
My recommendation is to just avoid the app and work with a solid textbook on a subject of interest. A list of everything looks appealing in its breadth, but in the end, you don't really know anything after you'd played with this app, and in one case, you'll get some misinformation.
Science Glossary from Vision Learning is free and requires iPhone OS 3.0 or later.