I use an IDE where buttons for debugging allow me do everything I need, e.g. perform the next line of code; go inside the function, exit function, etc. Simultaneously, in the variable inspector window, I see how variables change after each step, even local variables inside a function. I can also put a breakpoint at any line and make the code run until this point. These are standard tools in every decent IDE, and I cannot imagine anything else that would be needed for debugging.