EV3 SPIK3R on Mission 5 just keeps backing up
Perhaps a program that shows the ultrasonic sensor's reading in real
  time on the brick so I can move the bug around and see what the
  readings are?


You can easily view the ultrasonic sensors readings in real time. To do so, turn on your EV3 brick, navigate to the 'Brick Apps' tab (second from the right) and launch the 'Port View' application.

Use the EV3 buttons to find the port which your ultrasonic sensor is connected to. The ultrasonic sensor value should be shown.