I might be a bit sceptical about the benefits of a hypnosis app, too, but you're being unnecessarily harsh. It's not like hypnosis itself as a phenomenon is automatically nonsense. It attracts people who are into woo, so there's probably lot of nonsense being thrown around, but AFAIK the phenomenon is real and has been used with some success.
So maybe don't buy all the hype, but from your comments I get the vibe that you automatically dismiss the whole thing because of the h word. That's not necessarily right either.
https://news.ycombinator.com/newsguidelines.html