Development quote of the week

I'm not sure what you are looking for but there are various extensions that will customize the top panel. The Activities menu can be disabled with tweak tool (I have all those left-side menus turned off) and you can add stuff to the panel; one of my favorite extensions is "panel favourites" from frippery. I also add a system monitor to my top panel. You can also put in a separate bottom panel with a list of windows if that's what you mean.

However, I'm not sure if you can convert the top panel to have a window list. The center clock / updates app doesn't seem so moveable (but I've not really looked into it). This doesn't bother me because I've never really found window lists useful, even back when every desktop had them: I use ALT-Tab or even the HUD and that works for me (I know others have different tastes).