A free program for Android, by SimpleApps.
If you like chemistry, you should check out this app. This is a simple game that allows you to learn the periodic table of elements, which is the table that shows the chemical elements and the period in which they are found.
It has multiple options, and you can test yourself by choosing one of them. The first one is to select the type of element you want to find out the information about, and the second one is to choose the type of test you want to perform.
There are multiple tests, and you can perform them online and receive the results. You can learn about the symbol, the name, the most important properties, and how it is formed.