add-apt-key - This command line tool can be used to add a GPG key to your APT key ring.
Chocolatey - The sane way to manage software on Windows.
launchpad-getkeys - Launchpad-Getkeys is a script (comes packaged in a .
Homebrew - The missing package manager for macOS
Introduce PPA - The program saves you from having to open the console to add a new PPA.
Ninite - Ninite is the easiest way to install software.