A few years ago, the sight of the letters APP would have made teachers in England think of the Assessing Pupils' Progress assessment approach introduced by the government. Now, when they see those same letters they mostly think about smartphone and tablet applications, shortened to "apps." With the thousands of apps available in the Android, Windows, and Apple markets it can be really difficult to find the best ones. In addition, many teachers may be asking themselves which apps should be used for education. It is not an easy choice to make and surveying the app stores can be really time consuming. Apps also take up valuable space on handheld devices, slowing them down. In this article, the author discusses the best way to find apps that are truly effective and engaging for science lessons and evaluates the pros and cons of shifting to handheld technology in the classroom.