Fairly good
A decent tool. If you choose to revise it, I have two words of advice. First, the contrast between the lettering and the Warhammer background wasn't that good, so you might want to either find a different background or change the text color. Second, while it works alright, it would be useful to be able to specify a quantity of numbers to generate - rolling 20 dice takes quite some time with the current setup. While it might not be perfect, it's pretty good, and I like it.