How to play. Tap a card to pick it up, then tap a position to place it. Tap a card that
is already down to pick it up again and move it somewhere else; tap it once more in the card
list to put it back. On a computer you can drag instead, out of the list or straight from one
position to another. You name each block as well as filling it, and order counts, so a chapter
in the right block but the wrong position scores as placed but not positioned. Pick a single
block from the menu to drill just its chapters, with the name shown. Your board is kept in this
browser, so closing the page will not lose it. Reset clears it.