Comment by Merrillin

Good luck.

My two cents: I suggest making the software work first, on existing tablet(s).

Then once you have a product people actually want/use you can add the cost and complexity of building, inventorying, and shipping a physical product. Also, far more people would use your software than buy a physical version and you would have an audience of all the people using your software to convert into physical product customers as an upgrade.

Again, good luck!