Quick look / hear
Install GNOME Sushi on Ubuntu
GNOME Sushi is a simple feature that makes a major impact on your workflow. Its seamless preview prowess is such that, after a few days of use, you will begin to wonder how you managed without it!
To install GNOME Sushi on Ubuntu run this command:
sudo apt-get install gnome-sushi
GNOME Sushi is an alternative to macOS ‘Quick Look‘ for Linux desktops that use Nautilus, aka GNOME’s famous file manager.
You select a file in Nautilus, tap the spacebar, and an instantaneous (and usually interactive) preview of the file appears — no need to open a full app.
Sushi supports file previews for most plain-text documents, including scripts with syntax highlighting, as well PDFs, HTML files, and LibreOffice documents. Music and video file previews use the GStreamer framework to let you to seek/scrub through them.