MOPAC (http://openmopac.net/) is nice semiempirical code. It also calculates charges on atoms.
Is there a free GUI to display them please ? What I know, Avogadro diplays vibrations, JMol orbitals...but which GUI display charges on atoms ?
Both Jmol and Avogadro can color atoms by their partial charges provided that you have a way of passing that information to the GUI. MOPAC has a special output format to pass orbital and partial charge information to Jmol by using the GRAPHF keyword [http://openmopac.net/manual/graph.html], which produces a *.mfg output file. If you open up the *.mfg file in Jmol, you can visualize the MOPAC partial charges by right-clicking on the molecular display and going through the menus: "Color"->"By Scheme"->"Partial Charge".
To display the partial charges as numbers, go to the Jmol console (also in the right-click menu or File->Console drop-down menu) and type the commands "select all" to select all of the atoms and then "label %P" to display partial charges as the labels of the selected atoms.