Plots traced ultrasound tongue imaging data according to a polar coordinate system. There is currently support for plotting means and standard deviations of each category's trace; Smoothing Splines Analysis of Variance (SSANOVA) could be implemented as well. The origin of the polar coordinates may be defined manually or automatically determined based on different algorithms. Points for each category can be split into two groups (anterior and posterior) at the point of maximum curvature of each trace. User can specify rays to intersect various parts of the tongue; intersections along these rays serve as input for a pairwise t-test to measure significant contrasts between segments. Currently 'ultrapolaRplot' supports ultrasound tongue imaging trace data from 'UltraTrace' (< https://github.com/SwatPhonLab/UltraTrace>). 'UltraTrace' is capable of importing data from Articulate Instruments AAA. 'read_textgrid.R' is required for opening TextGrids to determine category and alignment information of ultrasound traces.