Lapsed User Re-Engagement Generator

Generate production infrastructure for detecting users who haven't opened the app in X days, showing personalized return screens that highlight what they missed, and optionally presenting win-back incentives to recover churned or lapsing users.

When This Skill Activates

Use this skill when the user:

• Asks about "lapsed user" detection or re-engagement
• Wants to handle "returning user" or "inactive user" scenarios
• Mentions "re-engagement" screens or flows
• Asks about "win-back" offers for churned users
• Wants to detect when a "user hasn't opened app" in a while
• Asks about "user retention" or "come back" experiences

Pre-Generation Checks

1. Project Context Detection

• Check Swift version (requires Swift 5.9+)
• Check deployment target (iOS 17+ / macOS 14+ for @Observable)
• Identify source file locations and project structure

2. Existing Engagement Tracking

Search for existing engagement or analytics infrastructure:

Glob: **/*Analytics*.swift, **/*Engagement*.swift, **/*Tracker*.swift, **/*Activity*.swift
Grep: "lastActiveDate" or "UserDefaults" or "scenePhase" or "applicationDidBecomeActive"

If existing tracking found:

• Ask if user wants to integrate with it or build standalone
• If integrating, adapt templates to use existing storage/events

3. Push Notification Setup

Search for existing push notification configuration:

Glob: **/*Notification*.swift, **/*Push*.swift
Grep: "UNUserNotificationCenter" or "UNNotification" or "registerForRemoteNotifications"

If push notifications are configured, offer push-based re-engagement as an option.

4. Conflict Detection

Search for existing lapsed user handling:

Glob: **/*LapsedUser*.swift, **/*WinBack*.swift, **/*ReturnExperience*.swift, **/*Reengag*.swift
Grep: "lapsedUser" or "winBack" or "returnExperience" or "daysInactive"

If existing implementation found:

• Ask if user wants to replace or extend it
• If extending, generate only the missing pieces

Configuration Questions

Ask user via AskUserQuestion:

1. Inactivity threshold?

   • 7 days (light engagement apps — social, news)
   • 14 days (moderate engagement — productivity, fitness) — recommended
   • 30 days (low-frequency apps — finance, travel)
   • Custom (user specifies days)

2. Re-engagement strategy?

   • What-You-Missed (highlight new content, features, or activity since last visit)
   • Special Offer (discount or extended trial for lapsed subscribers)
   • Fresh Start (reset onboarding highlights, re-introduce key features)
   • All of the above (tiered by lapse duration)

3. Trigger mechanism?

   • Show on app return (present sheet when user opens app after inactivity)
   • Via push notification (schedule local notification after X days inactive)
   • Both — recommended

4. Include analytics events?

   • Yes (track lapse detection, return screen shown, CTA tapped, offer redeemed) — recommended
   • No (skip analytics, just UI)

Generation Process

Step 1: Read Templates

Read templates.md for production Swift code.

Step 2: Create Core Files

Generate these files:

1. InactivityTracker.swift — Tracks last active date, calculates days since last use
2. LapsedUserDetector.swift — Evaluates inactivity against thresholds, returns lapse category
3. LapsedUserManager.swift — Orchestrator combining detection + experience selection + analytics

Step 3: Create UI Files

4. ReturnExperienceView.swift — Personalized "Welcome back" screen with what-you-missed
5. WinBackOfferView.swift — Special offer screen for lapsed subscribers

Step 4: Create Integration File

6. LapsedUserModifier.swift — SwiftUI ViewModifier for root view auto-detection and presentation

Step 5: Determine File Location

Check project structure:

• If Sources/ exists → Sources/LapsedUser/
• If App/ exists → App/LapsedUser/
• Otherwise → LapsedUser/

Output Format

After generation, provide:

Files Created

LapsedUser/
├── InactivityTracker.swift       # Tracks last active date in UserDefaults
├── LapsedUserDetector.swift      # Evaluates inactivity thresholds
├── LapsedUserManager.swift       # Orchestrator for detection + experience
├── ReturnExperienceView.swift    # Welcome back screen with highlights
├── WinBackOfferView.swift        # Special offer for lapsed subscribers
└── LapsedUserModifier.swift      # ViewModifier for auto-detection

Integration at App Launch

Attach to root view:

@main
struct MyApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
                .lapsedUserDetection()
        }
    }
}

Manual detection (if you need control over presentation):

struct ContentView: View {
    @State private var manager = LapsedUserManager()

    var body: some View {
        NavigationStack {
            MainView()
        }
        .task {
            await manager.checkOnReturn()
        }
        .sheet(item: $manager.returnExperience) { experience in
            ReturnExperienceView(experience: experience)
        }
        .sheet(item: $manager.winBackOffer) { offer in
            WinBackOfferView(offer: offer)
        }
    }
}

With custom thresholds:

let detector = LapsedUserDetector(
    recentThreshold: 7,     // 1-7 days: recently inactive
    moderateThreshold: 21,  // 8-21 days: moderately lapsed
    longTermThreshold: 60   // 22-60 days: long-term lapsed
)

Win-back offer for lapsed subscribers:

WinBackOfferView(offer: WinBackOffer(
    headline: "We missed you!",
    discount: .percentage(30),
    originalPrice: "$9.99/mo",
    offerPrice: "$6.99/mo",
    expiresIn: .days(7),
    productID: "com.app.premium.monthly"
))

Testing

@Test
func detectsRecentlyInactiveUser() async {
    let tracker = InactivityTracker(store: MockUserDefaults())
    tracker.recordActivity()

    // Simulate 5 days of inactivity
    tracker.override(lastActiveDate: Calendar.current.date(byAdding: .day, value: -5, to: Date())!)

    let detector = LapsedUserDetector(tracker: tracker)
    let category = detector.evaluate()
    #expect(category == .recentlyInactive)
}

@Test
func longTermLapsedUserGetsWinBackOffer() async {
    let tracker = InactivityTracker(store: MockUserDefaults())
    tracker.override(lastActiveDate: Calendar.current.date(byAdding: .day, value: -45, to: Date())!)

    let manager = LapsedUserManager(tracker: tracker, isSubscriber: true)
    await manager.checkOnReturn()

    #expect(manager.winBackOffer != nil)
    #expect(manager.returnExperience != nil)
}

@Test
func activeUserSeesNothing() async {
    let tracker = InactivityTracker(store: MockUserDefaults())
    tracker.recordActivity() // Just opened the app

    let manager = LapsedUserManager(tracker: tracker)
    await manager.checkOnReturn()

    #expect(manager.returnExperience == nil)
    #expect(manager.winBackOffer == nil)
}

Common Patterns

Detect on App Become Active

// In your App struct or root view
.onChange(of: scenePhase) { _, newPhase in
    if newPhase == .active {
        inactivityTracker.recordActivity()
    }
}

Show Return Screen

// LapsedUserManager determines what to show based on:
// 1. How long the user has been away
// 2. Whether they are/were a subscriber
// 3. What changed in the app since their last visit
let experience = manager.buildReturnExperience(
    category: .moderatelyLapsed,
    changelog: appChangelog.since(tracker.lastActiveDate)
)

Trigger Win-Back Offer

// Only show win-back to users who previously had a subscription
if detector.category.isLapsed && subscriptionStatus == .expired {
    manager.presentWinBackOffer(
        discount: .percentage(30),
        duration: .days(7)
    )
}

Gotchas

Background App Refresh vs Actual Absence

Background app refresh triggers applicationDidBecomeActive without user interaction. Use scenePhase changes to .active paired with the app being in .background (not .inactive) to avoid false positives. Track whether the user actually interacted (foreground time > threshold).

Timezone-Aware Date Math

Always use Calendar.current for day calculations, not raw TimeInterval division. A user who opened the app at 11pm and returns at 1am the next day has been away for 2 hours, not 1 day.

// Wrong - raw seconds
let daysAway = Date().timeIntervalSince(lastActive) / 86400

// Right - calendar-aware
let daysAway = Calendar.current.dateComponents([.day], from: lastActive, to: Date()).day ?? 0

Don't Annoy Deliberate Break-Takers

Provide a "Don't show again" option on the return screen. Respect user preferences — if they dismiss the return experience, increase the threshold before showing again. Store dismissal count and back off exponentially.

Avoid Stacking with Other Modals

If your app has onboarding, what's-new, or review prompts, coordinate with them. Don't show a return screen AND a review prompt AND a what's-new modal on the same launch. Use a presentation queue.

Testing Date-Dependent Logic

Inject the date source so tests can control "now":

let tracker = InactivityTracker(
    store: mockDefaults,
    currentDate: { Date(timeIntervalSince1970: 1700000000) }
)

References

• templates.md — All production Swift templates
• Related: generators/subscription-lifecycle — Subscription state management
• Related: generators/whats-new — What's New screen generation