It has to be listed to for the correct browser version of Firefox browser to work. And if it's not working then it's either out of date or incompatibly with the browser. It's up to the Addon Devs to update so it work if that is the issue or find out why the install doesn't work.

I've had onetab for a long time. When it works, it's great. But it occasionally just wipes out all the tabs I saved in it. Today it also wiped out all my regular browser tabs (pinned and unpinned). Enough--I deleted it. Beware.