As per @RSKGames' suggestion, I've added a couple of Swap mechanics to Tower solitaire.
You can swap any free cards in the tower, but only when they're on the same row.
You can also swap the topmost card amongst the dealt piles, too.

There's not a LOT of things you can swap, but hopefully it should be enough to make things a little bit easier in the 5 and 6 tower modes.

You can Play Tower Solitaire in the Card Games section of the Shoebox.