fastsleep.app does kinda similar thing... but instead of long podcasts, you are given something to imagine at a time interval.
Like if you hear "calm river", imagine that. If you hear "heavy rain over a tree", imagine that.
In short → Close your eyes, listen & imagine.
I wasn't able to find this, is it iPhone only?
I may have missed the joke but no, https://fastsleep.app/ is not iPhone only!
It's a progressive web app (you may install and use it both on android and ios) Simply visit the page and click Install. This may even be used without installation though... Even no sign-up is required to try this.