This periodic table app seems serviceable enough. Overall, a good alternative to the back cover or your high school chemistry textbook. Characteristics provided for each element are plentiful, but the "What is...?" blurb is underdeveloped. The one for silver, for example, could talk about its naturally occurring isotopes being nearly equally abundant. The attempt to list practical applications of the elements is good, but falls short. Osmium, for example, has none listed, though it is the densest element and is often found in fountain pen nibs and routinely used as a contrast agent for electron microscopy.
There is a prettier periodic table app out there, with photos of the elements, but it doesnt have nearly as many useful physical characteristics.