Software Center Kubuntu. Ubuntu Software Center is a utility for installing purchasing and removing software in Ubuntu a major part of Ubuntus overall software handling. The Ubuntu Software Center gives you instant access to thousands of open-source and carefully selected free applications.
But I highly recommend using it and please report any bug you can. Use command sudo apt-get install software-center to install the software center. Also there should be a GUI with a software button in a welcome screen at login if not Applications - System - Ubuntu MATE Welcome from which you can choose a software manager.
How to install the original one without reinstalling the OS.
Lubuntu right now lacks a Software Center as his big brother Ubuntu so Stephen Smally is developing a great app for this. Right click not left click on the Ubuntu Software launcher icon where your selections will be new window remove form favorites and show details. Software Boutique is not enabled however. The Ubuntu Software Center gives you instant access to thousands of open-source and carefully selected free applications.