Y PPA Manager - Y PPA Manager is a GUI tool to add, remove, purge, list and search for Launchpad PPAs.
npm - npm is a package manager for Node.
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.
Introduce PPA - The program saves you from having to open the console to add a new PPA.
aptitude - Terminal-based apt frontend.