Know what you mean, I was astounded when I took my first dose. It was like the usual relentless mind-noise had switched itself off, and I could just get on with stuff.
I noped out as soon as I saw it wanted a yearly subscription to activate a week-long 'free' trial.
I didn't trust myself to remember to cancel it in time and was disgusted at them weaponizing this dark pattern against ADHDers, so that was it for me.
If you go to the Play Store and search for the one-star reviews there are loads of people saying the same. And also for those that did try it, that it's mostly useless anyway.
I agree, and I think it's more harmful coming from successful founders, as so many people naïvely look up to them to provide guidance.
It's even worse than their usual "if I can do it - and I certainly have, just look at how awesome I am - then you can do it" spiel about business success.