The adhesive mat made it fairly easy to position the tiles. Mussel Bound is sold at Lowe's, but Home Depot has their own brand of a similar product. I'm not sure we could have done this without the mat!
Mussel Bound is a Lowes product. See MusselBound.com for any questions you have about the product. Their site even has a video showing how to use the tile mat.
The tile (Casablanca Orion porcelain tile) was purchased from Overstock.com, and was still available as of April 2017. For other sources, do a Google search for the specific name or search Arabesque Blue Tile to find similar tile.