There are 2 repositories under xfce4-panel-plugin topic.
A Dock-like Taskbar Plugin for XFCE
XFCE4 GenMon plugin: Switch between light and dark variants of a theme
A modern, minimalist taskbar for Xfce
A simple CLI to control Spotify via D-bus
XFCE4 GenMon plugin: Time tracking widget with TimeWarrior
DooM as an Xfce panel plugin
An i3wm-aware xfce4-panel plugin
xfce4-panel plugin to show the focused window title
XFCE4 GenMon plugin: Cryptocurrency price widget
A simple plugin for the xfce4-panel that displays your current Watson status.
Rescuetime productivity monitor applet for xfce4 panel
Xfce плагин для консольного аудиоплеера MOC
GitHub mirror of the xfce4-powertimer-plugin. Xfce4 panel plugin timer that shuts down computer after specific timeout.