Array Visualizer is a free, open source extension for visual studio. It is designed to display arrays (Jagged and up to 4D) while debugging an application.
This Visualizer automatically detects all local arrays once the debugger enters into Break Mode. It allows you to select any array and it will render it in 2D, 3D or 4D:
Sample 2D view:
Sample 3D view:
Sample 4D view (Displayed as a sequence of 3D arrays):
The visualizer uses the ToString() representaion of a class: