Well, it’s “just” a website and I would think any current tablet would be up to the task, and certainly any current laptop. The thing you’ll probably most want to pay attention to is the screen size (in pixels) and the physical size of the device (if you want to carry it around with you).
I do 99% of my BGAing on my iPad, and the tablet has a couple of advantages of a laptop, chiefly greater mobility, and that’s it’s always on with no booting up. The downside is a lack of a mouse and cursor so you can’t really “hover” over things in BGA. There are a number of alternate mechanisms to replace that but they are none of them perfect. You can buy special cases that give you a keyboard and trackpad, though; I just haven’t done that.
The advantage of a laptop is they tend to have greater screen resolution which comes in handy in some games, and the aforementioned “hover” capability. Plus laptops generally don’t take
tha long to boot up, and they are designed to be portable, of course.
Various online screen resolution testers tell me my screen resolution is around 954x1309, which is adequate but not great, but it
really depends on what sort of games you’re into. It’s perfectly fine for Wingspan and Azul, but a game with a big board or a lot of components may not look so good—things may be quite small or you may have to scroll around to see everything.
What sorts of games are you looking to play?
