You'll never know how clean your shower could be till you try the remarkable SPOT-X Hard Water Stain Remover.  It magically restores your glass shower screen to it's gleaming original state by removing that hard white overlay other cleaners just can't shift.  Moreover it actually polishes the surface so that after one use you mostly find that simple maintenance with just water and squeegee is sufficient for months after.
SPOT-X contains no harmful acids or solvents - so safe you could even sprinkle it on your green salad.