Screenfetch - Simple command-line tool that displays your distro's logo in text art form, your OS version...
CPU Frequency Selector - Cinnamon CPU Frequency Selector Applet
Neofetch - Fancier version of Screenfetch that displays colors and supports more platforms.
Archey 4 - Archey 4 is a system information tool written in Python
Udev Discover - A helping tool for udev testers, coders, hackers and consumers.
Winfetch by Max Bridgland - Winfetch by Max Bridgland is a command-line system information tool that you can use as an alternate to neofetch.