EMwaveRT is an app to aid teaching and learning of electromagnetics (EM) using mobile devices on the topic of plane wave reflection (R) and transmission (T). The app is designed to provide effective touch-based interactivity and visualization to help students better understand EM concepts. It is applicable to EM plane wave reflection and transmission for general oblique incidence and polarization. The instructor is able to input or change various parameters and rotate the view angles for interactive teaching. Based on the parameters, the 3D animations of incident, reflected and transmitted waves can be visualized in real time. This allows the students to identify clearly each wave and improves their learning of plane wave reflection and transmission. Through several preset cases of incident angles, the visualizations on mobile devices are illustrated. The app can be used to supplement the 3D TV program available for download from http://www.ntu.edu.sg/home/eeltan/TEL3DTV.html. User interface: - 3D view may be zoomed or rotated - text view may be zoomed or scrolled - double tap to revert to default view - touch on any underlined field to input/change value - use long slider to change the last field touched - use short slider to change the text transparency - use '|' to show/hide tangential components at interface