Rings circle the corners. Each of the 10 corners wears 16 rings: ring 1 is the few tiles touching the corner, ring 16 runs along the far edges of the faces that meet there. A turn slides a ring one face round its corner.
Turn a ring by swiping along it on the dial, with the ↺ ↻ buttons, or by dragging a tile on the 3D puzzle. Every tile rides three rings, one round each corner of its face, and the direction you drag picks which.
Pick a corner with ‹ ›, a corner badge on the dial's rim, or a tap on the puzzle near that corner. Cap turns every ring from the corner out to the one you touch.
Look around by dragging the space around the puzzle (or right-drag, or two fingers). Scroll or pinch to zoom; double-tap to reset.
Keys:[] corner, ↑↓ ring, ←→ turn, C cap, Ctrl+Z undo.
The solid is the gyroelongated square bipyramid (Johnson solid J17): a square antiprism capped by two square pyramids, and the only convex solid whose 16 faces are all equilateral triangles.