Screen Tax

Screen Tax is an app that turns screen time limits into real stakes. Every minute you go over your limit costs you money, paid either to friends in your accountability group or donated to charity.

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Inspiration

We kept setting screen-time limits and blowing right past them. The "Ignore Limit" button is free, and that's exactly the problem: there's no real cost to the tap. We wanted to fix the incentives: make every minute of overage actually cost something, either to friends who'll hold you accountable or to a cause you care about. Loss aversion is a much stronger force than a gentle iOS reminder, and we wanted to harness it.

What it does

ScreenTax turns a daily screen-time budget into a live financial meter. You pick the apps you want to limit (Instagram, TikTok, YouTube, Reddit, Snapchat, Netflix, Discord), set a daily minute cap, and choose a per-minute overage rate. Go over, and the app starts tallying what you owe, in real dollars. You can route the payout two ways: a peer-to-peer split across your accountability group, or a donation to a charity of your choice (Red Cross, Doctors Without Borders, UNICEF, WWF, Feeding America, Teach For All). A hero card shows your progress ring while you're within the budget; it flips red and shows a running tab once you're over. When you owe money, a "Pay friends now" / "Donate now" card appears to settle up.

How we built it

Pure SwiftUI iOS app, no backend. The architecture is split into a DemoSession that simulates usage (1 real second = 1 simulated minute for demo purposes), an OverageLedger persisted through UserDefaults, and LimitSettings / PayoutSettings stores backing the two tabs. The Home tab is a stack of cards (hero, settle, settings, apps, payout). The Accountability tab holds the friends list, charity picker, and mode switch. The project is generated with xcodegen from a project.yml so the Xcode project stays reproducible.

Challenges we ran into

  • Apple's Family Controls entitlement. The real Screen Time APIs (FamilyControls, DeviceActivity, ManagedSettings) require a paid developer account and a DeviceActivityMonitor app extension.
  • Asset pipeline. svgrepo's /download/ endpoint is behind Vercel's bot-protection challenge, so we had to fetch through /show/ with a browser User-Agent and tune the imageset Contents.json for vector preservation.
  • Card-based UI. Getting the progress ring, over-budget state transition, and settle flow to feel cohesive took several passes, including swapping a plain Form for a layered ScrollView of cards.
  • Keeping the ledger honest. The device can't be the source of truth for money in a real build, so we were careful to keep the overage accounting isolated behind a single OverageLedger so a backend can drop in later.

Accomplishments that we're proud of

  • A working end-to-end demo (limit, overage, ledger, and settle) running on a clean simulator in under a minute.
  • A polished SwiftUI interface: gradient hero card, animated progress ring, real company logos, icon-badge settings rows, and a settle card with a confirmation dialog.
  • Two distinct payout modes (friends and charity) with per-mode catalogs and UI, not just a toggle.
  • Zero reliance on paid Apple entitlements, which means anyone can clone, xcodegen generate, and run.

What we learned

  • SwiftUI's @Observable + small Store classes make a surprisingly tidy alternative to a heavier architecture for a demo-sized app.
  • Apple's Screen Time APIs are powerful but entitlement-gated, so plan the demo path separately from the production path.
  • Asset catalogs are pickier than they look (namespaces, vector preservation, required AppIcon set), and bot protection on free asset hosts is real.
  • Behavior-change products live or die on the feel of the feedback loop: the ring, the color flip, and the dollar counter matter as much as the accounting underneath.

What's next for Screen Tax

  • Real Screen Time integration. Wire up DeviceActivityMonitor behind the Family Controls entitlement so overages are measured from actual app usage, not a simulator.
  • Backend + auth. Stand up a service that owns the authoritative ledger, group membership, and who-owes-whom, since the device can't be trusted for money-relevant state.
  • Payments. Integrate a real payments provider for both peer-to-peer settlement and charitable donations, with receipts and a settled/unsettled history view.
  • Accountability groups. Invites, shared rules, group leaderboards, and streaks, turning solo loss aversion into social pressure.
  • Smarter limits. Per-app caps, weekly budgets, time-of-day rules (e.g., no TikTok before 9am), and grace periods.
  • Insights. A weekly digest showing where time and money went, with trends over the month.

Built With

  • asset-catalogs
  • deviceactivity
  • familycontrols
  • ios
  • managedsettings
  • sf-symbols
  • simctl
  • sv-g
  • swift
  • swiftui
  • userdefaults
  • xcode
  • xcodegen
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