I installed Ubuntu 18.10 yesterday, but I find myself missing some useful multitouch touchpad gestures.
In particular, I'd like to have a three finger drag gesture to move windows around.
On Ubuntu, you have to perform such a task with two hands, one to select the window and the other to drag around.
How could I implement this 3 finger gesture?
You can install a gnome extension that enables the feature you're looking for.
The download link to the extension is here.
You can also find instructions for installing gnome extensions in this article.
note: it requires wayland (and it only allows you to move windows with 3 finger drag; nothing else)