I'm searching for an online tool a friend used in an RPG once, no more than two years ago. The tool is a dice roller that adjusted the probabilities of an otherwise fair dice roll to make it less likely to roll the same number multiple times. So, if you rolled 1d6 and got a 4, your next roll of 1d6 would be less likely to be a 4 than it would be to roll 1, 2, 3, 5, and 6.
This made for pretty interesting play, since it enforced a broader distribution of values on dice that we wouldn't otherwise have seen. We still rolled on average the same number, but the distribution was wider.
Does anyone know where I could find this tool?