Said that I've never had a satisfactory zap history experience under BH but only under OBH (where you don't need any external plugin),
Because of your message, I rebooted under BH and I installed it without problem.
You won't have anything under the plugin panel (extension list, as you call it) because, as clearly written at the very moment you install it, you must press LONG BLUE and you'll find it scrolling the list.
Then you can launch it, then you have a list...
If you think it's worth to use it, good luck.
Under OBH, for instance, if you enable it you have just to press < or > and then browse.