This a remix of an excellent design by Daniel, located here: https://www.thingiverse.com/thing:5267945 I've added addtional 3 'leg's to the stacker so that grips the underlying tile more firmly. I found that three legs tended to make larger stacks unstable.

I've attached a Youtube video link show how the tile stacker can used: https://www.youtube.com/watch?v=U-TDUXOAkQ8