Not a tool per se, more of a workaround. But still useful. It's in fact a blend file with a simple node gropup that takes in a UV and rotates it randomly so a tileable texture can use it to remove repeating patterns.
Available here: https://www.blendswap.com/blends/view/92551
Available here: https://www.blendswap.com/blends/view/92551