HabitStack founder here. Your points are well taken! For some context, for the last few years, we've been a service company with a software product. You're seeing us at an awkward transition point to a product first company. So, sorry for the rough edges in the app! We're excited smooth them out.
What jumped out at you as needing immediate attention?
I'd be fine to pay such amount if the app was polished and had great UX. Not arguing with what you stated.
Seems like this is a common thing people need and I too tried to make an app for this. I gave up on it because the complexity grew fast, but my plan was to release it for free and have some sort of premium. I wanted to have a good product first before asking for money.