Ubuntu 16.04 LTS and later includes the ability to move the Launcher at the left to the bottom edge of the screen in Unity. If you’d like to put the launcher at the bottom of the screen, then press Ctrl+Alt+T to open a terminal window, then enter in this command:
gsettings set com.canonical.Unity.Launcher launcher-position 'Bottom'
This will set the launcher to the bottom of the screen:
To reset the position of the launcher to the left, run this command instead:
gsettings set com.canonical.Unity.Launcher launcher-position 'Left'