That thread took me on a trip down memory lane. Baristas Technolgies I used to use both copywrite and transcriva extensively, they unfortunately shut down at the beginning of this year.
I also used to use Audio Stretch https://apps.apple.com/gb/app/audiostretch/id571863178 for transcribing interviews. While designed for musicians I found it worked really well for audio, having the ability to slow down and backtrack by 15 secs.