Ubuntu Mate 18.04 applets alternatives, window picker

I usually have a lot of open applications, and I want to find a window picker alternative. Where would I go to find these alternatives?

For example, for KDE I would go to https://store.kde.org/browse/cat/105/ and find what I need there.

Is there an equivalent website I can go for applets compatible with Mate?

$ wmctrl -m                                                               
Name: Metacity (Marco)
Class: N/A
PID: N/A
Window manager's "showing the desktop" mode: N/A