[digitalbio]

Visualizing molecules / chemicals in 3D can be helpful when you're studying chemistry & biochemistry.  Molecule World will let you view both chemical structures (from PubChem), and molecular structures from the PDB or NCBI databases.  For molecular structures, you can also view the sequences.  Color keys help you identify elements and other features such as charge, hydrophobicity, and secondary structure.

https://itunes.apple.com/us/app/molecule-world/id863565223?mt=8

Here is an example of human insulin, colored by element, with a spacefill representation in Molecule World.