Plank dock is a lightweight applications launcher, Plank dock is developed by Docky Core team. It could be a great alternative to many dock applications if you are looking for simple dock application do the basic function of launching applications and arranging applications on the dock. Also, it’s a lightweight dock does not require big a mount of memory at all.
If you want to keep a running application on Plank dock simply right click on it and select keep in Dock.
Plank Dock Configurations
Plank Dock does not include a graphical user interface to customize the Plank Dock launcher. However you still can change Plank Dock Themes. Change the hiding mode “Auto hide, intelligently hide, Always on top”. Also, you can adjust Plank Dock icon size through the setting configuration file.
[How To]: Install Plank Dock On Ubuntu 17.04 (Zesty Zapus) Using PPA
You can install the Plank dock on earlier long term support releases [Ubuntu 16.04.2 LTS (Xenial Xerus) and Ubuntu 14.04.5 LTS (Trusty Tahr)] and the development release Ubuntu 17.10 (Artful Aardvark).