During my studies at the Faculty of Education, University of Ljubljana, I familiarized myself with a web application for graph manipulation called z0diak while I was attending courses on Graph Theory, Discrete Mathematics and Computer Mathematics. This application, which has a substantial set of functionalities, was developed by Luka Jurković for his diploma thesis in 2013. With it we can create visual representations of simple undirected graphs and then use a multitude of tools on the displayed graph.
In my years of using this application I realized that it has a few shortcomings and that I would appreciate new additional features. That is why I decided to analyze the application and its usability and upgrade it with new features and functionalities for my diploma thesis. Using a questionnaire and with the help of students who used the application regularly in their studies, the analysis of usefulness of the application has been carried out. According to the results of the analysis of student responses as well as technical and algorithmic complexities of the implementation, I discerned those features that could be added to the application with a reasonable amount of effort and added them. Apart from the existing functionalities the application now also supports the calculation and display of the girth and diameter of the graph, calculation of the graph degree sequence and functions which can help in determining whether a graph contains a Hamiltonian cycle or not. The thesis explains how these functions were implemented and also presents a demonstration of their usage on specific examples.