---

#swiftui #ios #indiedev #appdev

description: "How I built a privacy-first iOS app for BJD doll enthusiasts using SwiftUI, CoreData, and local notifications."
published: false
tags: swiftui, ios, indiedev, appdev

cover_image: /assets/bjd-cover.jpg

As an iOS developer and BJD (Ball-Jointed Doll) collector, I found myself managing my growing doll collection with spreadsheets, random notes, and calendar reminders. It was messy.

So I built BJD Doll Archive — a dedicated app that understands the specific needs of BJD collectors.

The Problem

BJD collecting involves a lot of tracking:

Doll details: brand, sculpt, model, face-up artist, purchase date
Care schedules: MSC coating refreshes, stain checks, light protection
Vendor experiences: which face-up artists deliver quality work, which shops are reliable
Photos: documenting customization progress

Generic inventory apps don't understand BJD-specific concepts like "face-up refresh cycle" or "resin yellowing prevention."

The Solution: SwiftUI + Local-First Architecture

SwiftUI for Rapid UI Development

SwiftUI made it straightforward to build the kind of detail-oriented forms BJD collectors need:

struct DollProfile: View {
    @State private var doll: Doll

    var body: some View {
        Form {
            Section("Basic Info") {
                TextField("Name", text: $doll.name)
                Picker("Brand", selection: $doll.brand) {
                    ForEach(Brand.allCases) { Text($0.rawValue) }
                }
            }
            Section("Face-up") {
                TextField("Artist", text: $doll.faceUpArtist)
                DatePicker("Last Refresh", selection: $doll.lastFaceUp)
            }
        }
    }
}

Privacy-First: No Backend

BJD collections can be valuable and personal. I made a deliberate choice to keep all data on-device:

CoreData for local persistence
No user accounts
No cloud sync
No analytics tracking

This means the app works offline and your collection data never leaves your phone.

Local Notifications for Care Reminders

The care reminder system uses UNUserNotificationCenter with custom repeat intervals:

func scheduleCareReminder(for doll: Doll, type: CareType) {
    let content = UNMutableNotificationContent()
    content.title = "Care Reminder"
    content.body = "Time to \(type.action) for \(doll.name)"

    let trigger = UNCalendarNotificationTrigger(
        dateMatching: type.nextDateComponents(from: doll),
        repeats: true
    )

    let request = UNNotificationRequest(
        identifier: "\(doll.id)-\(type)",
        content: content,
        trigger: trigger
    )

    UNUserNotificationCenter.current().add(request)
}

Lessons Learned

Niche apps have loyal users — The BJD community is passionate and underserved by mainstream apps
Privacy matters more than you think — Collectors appreciate that their data stays local
Simple > Feature-rich — Resistance to feature creep kept the app focused
One-time purchase > Subscription — For niche tools, users prefer paying once