Not me, I’m just putting the idea out there for anybody who wants to make them from rugged materials.
Shoot. I was going to design you an entire small-business inventory and control / customer management system. :)
1) The shape of the holster doesn't really look like any tablet I've ever seen. It's too close to square. Otherwise, it looks good from the outside. I don't know how many people would look at it that close, but it's just enough "not quite right" that I took notice of it.
2) The other thing is the manner of retention. It closes with magnets, which is good on one hand as far as opening the "Sneaky Pete" to access the gun, because velcro is just too noisy to open.
The down side of this is that when you take the gun out of the holster, the magnets are so strong that the holster closes back up with a resounding "thump". And if I'm in a convenience store and somebody comes in armed and dangerous, I want to be able to get my gun out without it making any tell-tale noise at all.
Matt makes a lot of good points, though. You need to have your gun with you all the time, because its' the bad guys who control the scenario, not you. You may think "I'll carry because I'm going to the bank", but it will probably happen at a time where you are not expecting it.