This app is available free either online, or as an application for a mobile device. Multiple lists of words or information (like list of ions or groups of ions) are available to review when searched by subject.
This site has short presentations for a multitude of academic subjects. Just click on the name above, which will link you to their website. Once you register via email or Facebook, you can search for nearly any topic you wish to view or review. Just type a keyword into their search window, and choose the level of review you need. You may need to register on the site, first. You can use your school-registered email to do so.