I use this cleaner in the kitchen, the bathroom, and for cleaning windows, tables, doors, walls... Basically, everything. It works fantastically well, cuts through grease and limescale and soap scum, and leaves surfaces shiny. As it has tea tree oil in it, it also acts as a mild antiseptic, antibacterial and antifungal, but is completely fine to use around asthmatics.
It's really, really complicated. Seriously. It will take you ages. Are you ready?
Step two. Fill the remaining half with cold tap water.
Step three. Add a few drops of tea tree oil.
Phew! I bet you're exhausted after that, aren't you?
For the best results, spray onto a surface, leave for a few minutes on particularly stubborn residue, wipe (or scrub if necessary) with a damp cloth, and then buff dry with a linen tea towel or similar.