Science

There are many apps that provide articles and other information in the sciences.

Articles

iSSRN
Created by the Social Science Research Network, this app provides access to more than 260,000 research papers in the social sciences and humanities from scholars worldwide. Articles can be emailed or viewed. This app is for the iPhone.
PubGet
Pubget for iPad delivers full text journal articles straight to your iPad. Read them as PDFs on the spot or save them to take on the go. Search everything in PubMed, ArXiv, JSTOR, IEEE and more. Dowling is working on integrating our journal access with this service to provide access to more content.
PLoS Reader
Read the most recent articles from the seven journals published by the Public Library of Science. PLoS Reader is designed just for the iPad and features a full-screen, page-turning interface.

Reference

The Elements: A Visual Exploration
A thoroughly stunning way to explore the elements. An ebook that explores each element from the periodic table with outstanding graphics, images, and more. $13.99
Molecules
This app displays three-dimensional images of molecules that can be viewed as either stick-and-ball or spacefilling. Molecules can be manipulated. It comes with a basic set of molecules and more can be added from either the RCSB Protein Data Bank or NCBI’s PubChem. Free.
Scientific Graphing Calculator
Basic scientific graphing calculator that includes unit converters, constants, make a table of the values of any function you care to enter, and more. If you need more than this provides, a paid version is also available.
Periodic Table Explorer
For $0.99, this app contains in-depth information about all of the elements of the periodical table, including their compounds, physical properties, isotopes, spectra, and reactions. It also includes images of each element.
Science Glossary
A free dictionary of terms as well as brief biographies. Definitions provide related terms as well as links to science learning modules. This app is provided by http://www.visionlearning.com/