Chemistry Helper is a nice, simple reference app. The menu includes the following topics: a periodic table with links to wikipedia, a tool to calculate molecular masses of compounds, a table of polyatomic ions, constants, solubility rules, tools for calculating molarity and volume of solutions, tools for converting between units commonly used in chemistry, a table of reduction potentials, organic chemistry functional groups, IR, H1 NMR and C13 NMR spectroscopy tables and a table with common ligands. I think it would be useful for any student studying chemistry.
A+ Academic Apps for Androids 