Use Point to drop an event marker. Use Straight line by click-dragging. Use Text to place small boxed labels onto the diagram. Use Move object to grab existing geometry and drag it elsewhere. Use Eraser to remove shapes by click or drag. Use Axes to temporarily hide individual axis lines or labels by clicking on them, or to show only grid lines parallel to one chosen axis. Hold Option while placing points or drawing lines to bypass grid snapping. Shift+drag still repositions existing geometry as a shortcut. Rectify view slides the page rendering from reference-orthogonal to boosted-orthogonal without changing the relative velocity. With Equal-distance hyperboles on, Clip snaps line endpoints to the nearest displayed hyperbola. Use the hyperbola spacing box to choose how densely those equal-distance curves are drawn. Hyperbola points mark sample events on the equal-distance curves and light cones. Bell's rockets adds the standard equal-lab-separation acceleration case with a draggable probe event, its local simultaneity slice, and optional locks that match the boosted frame to the probe velocity and keep the chosen rocket pinned to its launch x-position. Twin paradox adds a home twin, a traveling twin parametrized by the traveler's proper time, and a local simultaneity slice showing which home-twin age the traveler counts as simultaneous. Hide axes & drawn lines temporarily clears the frame axes and user-drawn line segments without deleting them.