A lot of facts, figures, and formulas are associated with chemistry, and even experts have to access a reference book now and then. This app not only gives you nearly instantaneous access to all the pertinent details about any element, it also lets you doublecheck manual calculations with its built-in calculator. The full Periodic Table is displayed in landscape view, as shown above. Unfortunately, selecting the correct element from this screen can be a little trying because the squares that represent them are tiny. Fortunately, elements can also be searched for by name, symbol, and atomic number.