In order to install 8tracks with Ubuntu Software, launch Ubuntu Software,
search for 8tracks and finally click the Install button.
a Linux terminal emulator,
type flatpak install nuvola eu.tiliado.NuvolaApp8tracks and press the Enter key to install this package.
Then log out and log in back to let your desktop environment (GNOME, Unity, etc.) find out that
a new application has been installed. Otherwise, you may see "Unknown Application Name" in the menu bar,
mismatched application icons and other funny bugs.
You should be able to find 8tracks in a list of installed applications. If not, you may have forgotten
to log out and log in and your desktop environment (GNOME, Unity, etc.) has not find out yet
that a new application has been installed.
Alternatively, you can launch 8tracks
from a terminal: