I've recently started using 30 Seconds 1L Shower Cleaner and have found it really great. You don't need to scrub. Spray it on and leave it to do its work. You can then rinse it off later. For the initial clean, you might also like to grab some Selleys 750ml Rapid Mould Killer Remover. Make sure you open up all the windows for ventilation.
For the walls, I like to use some Sugar soap and magic erasers to remove mould growth. I then follow this up with a spray mixture of 1 part clove oil to 9 parts water. This kills the spores and prevents the mould from coming back very well. Personally, I've found the clove oil stops the re-growth of mould for longer than bleach does. It's also less potent on the nose.
After you have finished cleaning, consider the reason why the shower was so mouldy. Perhaps it just hadn't been cleaned in years, but if there is no exhaust fan, it would be worth installing one. Since a bathroom is a high humidity environment, it encourages mould to grow. The more ventilated the space is, the less likely mould growth will set in.- MitchellMc
We still swear by CLR Kitchen and Bathroom cleaner (available at Bunnings). It sure does stink, but gee whiz, it cleans bright and shiny. We only have to do ours once a month. Tip: Once finished in the shower, quickly rinse soapy residue off the glass. Cuts down cleaning time. - darylhewston
Shower windows / screens aren't the same as other windows in your home. For those other windows dishwashing liquid is probably the best followed by car washing soaps. These cleaning agents are designed to cut through grease and grime.
For the shower, CLR: Calcium, Lime and Rust is just the ticket. But you will have to be vigilant; once a day for a little while until the glass is clean, then regularly to keep it that way. 30 Second Mould Remover will also do the job. - PJA