You will get the pop-up menu if you right click with the mouse on the picture. The items in the pop-up menu are (along with some standard zoom and save function):
Properties:
This is where you select files to plot and everything else about the picture and simulation setup.
Toolbar:
With this button, you can click on the picture to visually insert the particles you want to trace.
This button starts the simulation.
File name legend:
As default, the file name and path of your input data file is shown on the plot, but you can switch this off but selecting this menu item.
Move North Arrow and Convergence Indicator:
Selecting one of these and afterwards clicking on the desired new spot will move the North Arrow or the Convergence Indicator to the new spot. But of course only if the icon is already on the plot.
Insert track starting points:
Selecting this menu item, you can click on the picture to visually insert the particles you want to trace. This works the same way as the toolbar button.
Calculate tracks:
This menu item starts the simulation in the same way as the toolbar button. 
