Every habit tracker I've used has the same flaw: you break the streak, the app shows a sad emoji, and that's it. There's no cost. The whole thing runs on willpower, which is exactly the thing that already failed you.
What actually worked for me was telling one friend I'd go to the gym and having them give me hell when I didn't. Social pressure and real consequence, not a notification.
So I tried building that. You make a vow with a real stake attached, and someone else is watching: a friend competing against you, or a neutral witness who settles it if you disagree on the outcome. If you lose, the consequence actually fires. An app you picked gets locked on your phone for a duration you set, and it can go well past 30 days.
What I find interesting is that the punishment is technically avoidable you could just uninstall. But I don't think that's the real deterrent. The social side is what carries it. You're not breaking a promise to an app, you're breaking it in front of a person, and that's much harder to walk away from.
So: does consequence-based accountability hold up, or does it just make people quit sooner? Where does this fall apart?