Castor is a household app for grocery, pharmacy and beauty lists, with weekly, fortnightly and monthly budgets. Each list has a ceiling, items are marked as essential or extra, and extras stay locked until the essentials of that list are done.
It runs as a PWA on this site. Data syncs with Firebase (Auth and Firestore) so the same household can use it from more than one phone, and it still works offline. Months can be archived and exported to PDF.
The interface is in Portuguese, built for day to day use rather than as a demo. Astro hosts the page, Vue drives the UI, and the numbers (ceilings, leftovers, extras) are calculated in a small dedicated layer so the rules stay consistent.