GeoGebra is the most well-known Dynamic Geometry Application (DGA) in the world. Many researchers are interested in GeoGebra as a tool to make interactive mathematics resources. Here we focus on a snapping function in GeoGebra, which is a kind of general feature of DGA: the mouse cursor is attracted to a specific position or a specific object and it looks like magnetic attraction. Snapping to a lattice point is originally implemented in GeoGebra. Some examples of extended snapping function are introduced in GeoGebra Material platform. The goal of this paper is to argue the effectiveness of snapping function in GeoGebra from the viewpoint of making educational materials. We propose some positive examples of resources with snapping functions. We also use GeoGebra resources both with and without snapping functions, and report the results of questionnaires about these materials in a class of a simulated lesson.