Carbon 12

This app has lots and lots of things for periodic table. It has a full periodic table in it. And also each element has its own page where you can see its all details. It covers details like Element name, Atomic number, atomic mass, Electron Configuration in both form, its category, Melting point, boiling point, Year discovered, discovered by, Van Der Waals radius, Atomic radius , Oxidation states, Bonding type, Electron affinity, Electron Negativity, its appearance, all of its Ionisation energies for each electron and also its CPK Colour. Using all these, one can master whole periodic table and periodic table is one of most important part of Chemistry. And the whole app is open source at: https://github.com/hemish11/carbon-12. With this app all can make proper use of periodic table and the best thing is that all the features and details as well as all 4 themes are free. You don't need to pay for anything and can use full application forever.