Yellow spots in the tub or shower can be removed by putting a slurry of 100 grams salt and 1 dl of vinegar on them. The yellow comes next off without a hitch.
How to clean you bathroom?
For the bathroom, I use a mop stick with a clean cloth around it. I make the cloth wet with water and vinegar. Then "mop" tiles along the walls. Wipe dry with a clean cloth (I love microfibers) and shiny again limescale against you. The mirrors, faucets etc. I do then with the cloth with which I wiped the walls. The floor I do finally with the same mop.