The GTG Mathematics in Physics Education follows the philosophy of supporting physics understanding by the conscious use of mathematical structures in physics teaching. We discuss the possible roles of digital tools in promoting physics understanding by fostering sense making of computational models, using geometrical visualizations or interpreting app-generated diagrams in a physics context. We look into three types of digital tools: (a) Smartphone apps that allow data collection from the phone’s internal sensors to effortlessly produce graphical representations of the data. (b) GeoGebra, that combines different mathematical representations and allows their visualization and manipulation. (c) Computational modeling via Vpython where students can build or manipulate a computational model and compare it to experimental results. We will describe the potential of these tools to improve understanding of different mathematical features in physics, as well as obstacles that educators should take into account. In addition we present some empirical findings concerning graphs from smartphone apps and experiences from teacher professional development.