I love this addon. I use it on two sites and my users just love it. However, since I upgraded to XF 2.0.10 on both sites, the collapse/expand button has moved to just under the category titles on both sites.
Works great on our custom theme as well as the base theme. Simple to install, and doesn't require any configuration. I'd hoped to find something like this as we used to have Toggle [me] for XF1. Thanks!