Someone mentioned making a grid shaker from full size boggle but unfortunately, the travel size has one less row and column. I made my own handheld grid shaker a slightly different way.
What size is it? The acrylic box is 3 1/8 inches cubed. The marbles are 9/16 inch.
Which team starts? I wanted a purple marble for the alternating team, but I didn't have a purple, so I used a green. The whites are neutral and then there's the black/red/blue marbles we are familiar with. Instead of drawing which team starts, you can pick for each game and include the green marble with your teams colors.
What is the square piece inside? The acrylic box is slightly too big to work properly. Look at this picture of the box on its side showing what happens the half of the time when the marbles did not settle in the preferred pattern. The inclusion of the 3d printed square, ensures the pattern is true every time. It is held in place with clear silicone.
Is that paint? It is white Plasti-Dip. Hopefully, it will take an impact if someone drops it.
I have not used it yet but a more tactile game is going to be more fun.