In October 2014, an interesting new app became freely available in the Apple Store®. It is called PhotoMath®: (1) Hold a phone or tablet up to a mathematics problem in a textbook; (2) The app shows the answer to the problem; and (3) Select Steps to see the step-by-step process for getting from the problem to the solution. The app works for simple operations such as addition and subtraction as well as fairly complicated-looking equations. Equation solvers (e.g., computer algebra systems, or CASs) are hardly new. Many handheld calculators can solve much more complex problems than PhotoMath. Such tools often ignite debates in mathematics education. Even the four-function calculator was (and still is, in some contexts) a controversial tool in the classroom (Starr 2002). What guidelines should teachers use to decide whether and how to allow PhotoMath to play a role in their classrooms? In this article, the authors consider the ramifications of the PhotoMath app by relating it to other tools that are commonly used in the mathematics classroom. They then consider some of the benefits and limitations of different ways of responding to its presence.