Here's my initial idea for a web interface for the robot: a 5x5 grid of buttons.
Since the robot is on a truck chassis, there aren't controls for rotating in place, but there are directional buttons for forward, reverse, forward right & left and reversing right and left indicated by the single chevron.
The double chevron indicates faster movement in that direction.
X button in center is all stop/off.
Top row has options for toggling LED lights and an ultrasonic range check.