Singapore Airlines is unfortunately not one of my sponsors, in this project of going everywhere, but they do offer all transit passengers a free city tour of Singapore.
If you have a stopover of more than 5 hours, you can explore a bit of Singapore for free. An awesome idea other airports now have implemented. I experienced this back in March and made the video below. There is no reason not to do it, as it’s free for anyone. I have been to Singapore 9-10 times in the past, but always nice to be back.