Wallpaper group 11 of 17, p4m: a square lattice, point group 4mm, 8 operations per cell, orbifold *442. Written p4mm in full.
Molecular point groups with their operations and character tables, the 230 space groups with a cell builder, and the 17 wallpaper and 7 frieze groups drawn live. The tool needs JavaScript, and WebGL2 for the 3D views; these are the pages it offers: