Show HN: Kubbo – build a medieval city with your daily habits (kubbo.app)

I've been building mobile apps for 10 years, mostly for clients. 2 years ago I decided to build something for myself. Kubbo is a habit tracker where completing tasks builds a medieval city. Miss 2 days and a random building gets buried. 30,000 downloads, 4.8 on the App Store. Built with Flutter. Happy to answer questions.