You should touch any block agent with the finger tool to grow a Cartesian grid (the large blue spot in the lower right corner should be easy to hit with a finger tool).
By increasing the "depth" parameter in the simulation properties, you can increase the iterative limit of the Mandelbrot set.
Using the finger tool, you can rebuild the grid from any point which becomes the center of the viewing space, and with a zoom in factor set in the simulation properties.
Setting the zoom to 1.0 at any viewing resolution will re-center, increasing or decreasing the zoom will recenter AND zoom when any grid element is touched by the finger tool.