Synaptic Package Manager lets me install, uninstall or reinstall a software item. It lets me search for a software item as well. It also lets me sort software items by sections, for instance, editors and multimedia.
I can open the Manager by clicking on "System", "Administration" and "Synaptic Package Manager".
I can see the status of the software items by clicking on "Status". I can view the installed software items and those not installed. I can switch back to the sections view by clicking on "Sections".
To install Synaptic Package Manager, issue the command in Terminal:
apt-get install synaptic
Here are two screenshots: