I like widget bars (if only because they tend to provide an analogue clock that I consult occasionally),
so over time I’ve used AB5k (Glossitope), WidgetFX, then Google Desktop, when the later was discontinued I thought I should do my own, so that it would only be discontinued when I’d stop maintaining it myself.
Eventually I started working on one using JavaFX.
Since I could not find a ‘proper’ way to have a side bar, I tried with this project to add some AppBar (doc and Petzold’s article on the subject) support to OpenJFX.
It currently supports adding a main window that is an AppBar on any of the 4 edges, resizing and transparency.