UX/UI redesign and prototype for a fully responsive PWA HIIT Timer -- 2

I have this website (tool for myself and friends), a HIIT Timer that allows you to set timers, either a single use one, or a set with rounds, cooldowns, prep times... And I want to revamp it, make it look more 2022, so I'll need a UX/UI design and prototype, with current and planned features, with a new (or same, doesn't matter to me) color scheme, possibly a logo, the whole rework!

New features that should be integrated in the new design:

1.- Possibility to sign in/log in
2.- Save/Load saved presets (named, obviously)
3.- Share presets
4.- Possibility to install it as App (PWA)
5.- Settings
5.1.- Dark/Light theme
5.2.- Sounds (for timer, cooldown and prep)
6.- Feedback/Suggestions
7.- Non-invasive ads

Lastly, this tool although simple, is being used from mobile phones, pcs, and TVs, so the UI should be responsive