I built one central app around the things a household actually repeats: shared events with notifications, shared notes and lists, and a recipe book where one tap adds every ingredient to the shared shopping list. It's a Progressive Web App built in React with Supabase for the shared data, so it installs on any phone without an app store, and event reminders arrive as push notifications that each user can switch on in the settings.
The real design brief was adoption. A system only gets used if people feel at home in it, and my target user was clear: my partner. So the visual design was built around her taste first, and features came second.