If you want to customize macOS, Hologram Desktop is a very easy tool to do so.
Not only do you have the choice of over 5 million background images, but you also get many widgets with which you can design your desktop the way you like it. For example, there is the moon phase to display, system information, quotes and more.
The basic version of Hologram Desktop is free, a Pro version is available for just over 10 euros. With this you can download as many wallpapers as you like, unlock all 50 widgets and create your own folders to save them. Furthermore, there are theme templates, so templates with which you can start to customize your desktop.
You can download Hologram Desktop here.
