If it's just a set of steps, rather than boxes with a combination of things (like setting, character, plot), then why is it more complicated than a bingo card? It should be possible to lay out just a row of boxes, and use any of the standard lists to fill them. That way if you wanted settings the character visits in order, or characters they meet along the way, or the timeline of crisis points, the same strip of boxes could yield that depending on what list you plugged in. And we already have lists for plot, setting, character, and theme.

Though I admit it would be rather awesome to have a graphic option that would actually lay out the seven boxes along a peak line, or a time line that could be printed out as a chain. Hrm, a more complicated version would be if you could select how many steps in the chain you wanted, like we have 3x3 or 5x5 bingo cards now.