Markva — Stock Market Predictor and Tutor

Built for the RevenueCat Shipaton by Nathan Kumtakar and Arya Kakani.

Markva is a combined "financial life" app: mock/paper stock trading + a personal expense tracker, wrapped in one app so a RevenueCat subscription has enough real feature surface to gate meaningfully. Everything financial is simulated — no real brokerage, no real bank connection, no real money at risk. The pitch is educational: practice trading and budgeting with zero real-world downside, while learning the underlying concepts through a full Learn tab (lessons, flashcards, quizzes, daily trivia).

For Shipaton judges — try it in two minutes

⬇ Download Markva-Judge.apk and install it on any Android phone (allow installs from unknown sources when asked). No account, no keys, no setup.

1. Open the app and tap "Yes, I'm a judge".
2. Go to Settings → Upgrade (or tap any locked feature) and pick Pro or Max.
3. The real RevenueCat paywall opens at the regular prices. Tap the purchase button, then "Test valid purchase" in the RevenueCat Test Store sheet.

That's RevenueCat's Test Store, so no card is needed and nothing is charged, but the entitlement comes from RevenueCat exactly as it would for a paying customer. The app installs as "Markva Judge", alongside any other copy.

Friends & duels: Markets → Portfolio → people icon → create an account (any email, no verification). Markva Bot has already sent you a friend request; accept it, tap Challenge, and the duel starts right away. You can also add a friend by email, or create a family and share its invite code.

App code lives in Expense Tracker/ — that's the actual Expo project root. See ARCHITECTURE.md for a full map of the repo, and CLAUDE.md for the complete build history and design rationale behind every feature.

RevenueCat integration

RevenueCat gates a real three-tier subscription (Free / Pro / Max) across the app — see constants/subscription.ts for the full feature matrix. Highlights of the integration:

• react-native-purchases + react-native-purchases-ui for native paywalls, entitlement checks, and customer-info sync (services/purchases/).
• Handles the real-world gap between RevenueCat's default umbrella entitlement and a per-tier "pro"/"max" check, rather than trusting the SDK's own presentPaywallIfNeeded to match tier-for-tier.
• Distinguishes a genuinely unconfigured project (falls back to a local dev-mode tier switcher) from a configured but failing paywall (surfaces the real RevenueCat error instead of misdirecting the user).
• Judge mode: a dedicated internal build variant shows "Are you a judge?" on first launch. Yes routes every subscribe button through RevenueCat's real Test Store — the actual paywall UI, resolved against a real Offering, unlocked only once a judge taps "Test valid purchase" inside RevenueCat's own Test Store UI (a real CustomerInfo/entitlement, no Play Billing, no card). This exists specifically so the RevenueCat integration is reviewable exactly as a paying user would experience it. See constants/judgeMode.ts and CLAUDE.md §5.11 for the full design.

Feature tour

Tab	What's there
Home	Net worth/P&L, watchlist, quick actions, a "Weekly Recap" Wrapped-style card deck
Learn	Streaks/badges, spaced-repetition topics, flashcards, an AI-narrated daily challenge, a daily trivia battle vs. a seeded AI opponent, and 4 lesson modes per course (Standard / ELI5 / AI-generated Story / Pro+Visual with curated video)
Markets	Searchable stock list (100 curated tickers, plus live fallback search for anything else), a trained price-direction predictor, forecast/sentiment, product scanner (photo → AI company ID → live price/news), a $100k-vs-AI investing arena, and Portfolio (multi-portfolio, net-worth history, dividends, auto-invest, leaderboard, friends/family/duels)
News	InShort-style swipeable market news feed with an automatic AI explainer per headline
Expenses	Filterable list, category breakdown, AI spending insight, budgets, savings goals, CSV export
Assistant	General + per-symbol AI chat with history and quota/key management

Tech stack

Expo SDK 57 · React Native · TypeScript · expo-router · Zustand (persist + AsyncStorage) · react-native-reanimated · RevenueCat · Supabase (optional accounts/social features) · Sentry · direct HTTP integrations with Claude, OpenAI, Gemini, and OpenRouter for every AI feature (no SDK abstraction layer).

Running it locally

cd "Expense Tracker"
npm install
npx expo start

To run judge mode from source instead of the APK, use npm run judge (needs EXPO_PUBLIC_REVENUECAT_TEST_STORE_API_KEY in .env for the Test Store paywall; without it, the plan screen offers a labeled offline Max preview).

The app is fully functional with zero environment variables set — every integration (RevenueCat, live market data, AI providers, Supabase, Sentry) degrades gracefully to a local/demo mode without a key. See Expense Tracker/.env.example for what each optional variable unlocks.

Privacy

See Expense Tracker/PRIVACY.md for the full data-handling policy — local-first storage, what each third-party integration receives, and the under-18 compliance layer that gates AI photo uploads, accounts, purchases, and engagement nudges for teen users.

License

MIT — see LICENSE.