• Chart.js 
  • Chart.js can be used to create graphs
  • Custom built-in widgets can be used to simplify the creation of the graph
  • These widgets include, but are not limited to: graph size, location, legend size, legend location, x-axis labels, and y-axis labels.

The Placker plugin for Trello is a great tool for project tracking, allowing story estimation, points, dependencies, etc. directly on Trello.  It will also automatically generate a Gantt chart based on the Trello card setup.  NOTE: this is only free for 2-3 weeks.  A second option (Tableau) is below.

Tableau is a great tool for all sorts of graphics/visualizations of data.  It is also a very useful alternative to Project for making Gantt charts (connect to an Excel sheet, similar to guidelines at https://www.tableau.com/trial/gantt-chart-template?utm_campaign_id=2017049).  Tableau is free for students with a .edu email address (https://www.tableau.com/academic/students).

• Visio-like software for Macs - (Lucidcharts) - This is a web-based SaaS tool that you can use to do diagrams.  It's an application you can use through Google Docs.  The free tier limits the amount of shapes and models you can make.

• GeoMapping functionality
  • Here's an easier alternative to Google Maps - MapBox.com! Example: http://austinartmap.com/ 
  • OpenStreetMap - create individual maps with static information; open source, free, low learning curve