MacBook (12 inch early 2016). OS X 10.13.6
I restored my time machine backup to a new, to me, computer. Unfortunately Better Touch didn't seem to restore (I may be wrong about that more later).
SO, I installed the dmg file from when I purchased it. This was a big mistake because the BT database DID restore - clearly there have been changes.
The icon showed up in the toolbar but no BT functions worked. And if I tried to change anything I just got a screen full of "Cannot save" dialog boxes.
I hunted down the database and deleted it. I then installed BT again with a fresh download. Now it works. BUT the toolbar icon is missing. This is what makes me think it is a bug since this is probably what I had after the TM restore.
I haven't found anyone else complain about this. And it is far from serious. Still, I miss being able to go into settings etc without snaking though launchpad.