Avogadro is described as «advanced molecule editor and visualizer designed for cross-platform use in computational chemistry, molecular modeling, bioinformatics, materials science, and related areas» and is an app in the education & reference category. There are more than 10 alternatives to Avogadro for a variety of platforms, including Windows, Linux, Mac, iPad and Android. The best alternative is Chemaxon Marvin, which is free. Other great apps like Avogadro are BKchem, Calistry.org, Gnome Chemistry Utils and Jmol.
