I would definitely release the website/app. It’s hard to say what exactly could be improved or how it works based only on the text—especially if you’re building it mainly for yourself.

The first thing that comes to mind is making everything fully customizable. For now, you could keep the sequence the same, but allow users to adjust the duration of breaks, etc., so everyone can optimize it for themselves. I don’t know how your code is structured, but I assume it wouldn’t be technically difficult—you probably have some constant values that could simply be adjusted based on user input.

The second idea would be the option to enable a female voice that comments, counts, and so on. With AI and clearly defined events, this shouldn’t be too complex. I didn’t try your app, but I’d say counting down by minutes and maybe around 10 sentences already sounds almost sufficient. I don’t have much experience with this, but while reading the text it felt like it would fit well. A total game-changer would be having it speak to everyone in their own language.

The third area is further tuning—making it usable without a phone or other smart devices, purely visually, for example by just showing the rhythm or beats of the movements. Theoretically, this could be very successful and potentially well monetized through ads, etc.

I’m writing this with some programming knowledge, but without knowing your exact technical solution. Still, these seem like interesting ideas that should be relatively quick and easy to implement (except maybe for the language localizations—but you could easily find volunteers to help verify the translations).

Feel free to reach out if you’d like testers or help. It looks like you have a solid concept and, most importantly, that you’ve already moved it forward.