Development of a Mobile App for Bus Tickets

We develop mobile apps for bus ticket sales with integration into carriers' accounting systems. Unlike aviation, where standardized GDS systems operate, bus ticketing faces fragmented APIs, outdated protocols, and a lack of a unified carrier registry. Many carriers still use outdated XML protocols without REST support, so we adapt parsing for each system—from 1C to specialized 'Avtovokzal' ticket offices. It is crucial to maintain response speed: the average carrier API response time must not exceed 500 ms, otherwise users abandon the app. That's why clients need a complex integration system, offline mode, and flexible refund logic.

Our team has extensive experience in transport app development, having delivered 15+ projects for bus carriers and aggregators. We guarantee quality at every stage—from analysis to post-release support. Contact us for your project evaluation or get a consultation on integration.

Data Sources and Integration

Three main paths:

• Carrier's own system. We develop for a specific carrier—they have their own schedule and cash register system (typically Avtovokzal, Radar, Transinfo, or 1C). We integrate directly via REST or XML API. Reliable but closed audience.
• Aggregators. Tutu.ru, Busfor, CheckMyBus provide APIs for white-label partners. Access requires a contract. Tutu API is REST/JSON with up-to-date schedules for most routes in Russia and CIS. CheckMyBus is for international routes.
• Own aggregation. Parsing and direct contracts with carriers—the most expensive and labor-intensive option, but gives control over data and margin.

Integration with SBP allows faster payments than cards, and a 0.4–0.7% commission saves up to 30% on acquiring costs.

Why Bus Apps Require a Special Approach?

Unlike airline tickets, where data is standardized via booking systems, bus carriers use dozens of different accounting systems with incompatible protocols. Some carriers do not support electronic tickets—only paper ones, which must be explicitly shown in the UI before purchase. Additionally, seat layouts in buses vary greatly: from simple 'seat available' to a layered grid with aisles and different classes. This makes the UI more complex and testing critical. According to App Store Review Guidelines (Section 4.2, 5.1), such apps must explicitly indicate all restrictions.

How Does Integration with a Carrier Work?

1. Audit of the carrier API—study documentation, test endpoints, identify limitations (e.g., no basket or refund support).
2. Development of an adapter—write a module to convert data to a unified format. Use Codable (iOS) or Kotlinx.serialization (Android).
3. Testing on live routes—run up to 100 scenarios: purchase, refund, seat change, delays.
4. Deploy to sandbox—carrier tests on their own data.
5. Release to App Store and Google Play—ensuring compliance with App Store Review Guidelines (sections 4.2, 5.1).

Search and Seat Availability

Search: origin-destination, date, number of passengers. Autocomplete for stops via UISearchTextField (iOS) with 300 ms debounce or SearchBar + Flow in Jetpack Compose. The stop database is cached locally: the full list of Russian bus stations is about 3000 entries, loaded on first launch and updated weekly.

Seat selection. Not all carriers support a bus seat map with specific seat selection—some just sell a 'seat on the bus'. When a map is available, we render it as rows and columns from the API, marking occupied seats.

// SwiftUI: bus seat grid
struct BusSeatMapView: View {
    let seats: [[BusSeat?]] // nil = aisle

    var body: some View {
        VStack(spacing: 4) {
            ForEach(seats.indices, id: \\.self) { row in
                HStack(spacing: 4) {
                    ForEach(seats[row].indices, id: \\.self) { col in
                        if let seat = seats[row][col] {
                            SeatCell(seat: seat)
                        } else {
                            Spacer().frame(width: 32)
                        }
                    }
                }
            }
        }
    }
}

Electronic Ticket

After payment, we generate a PDF with a QR code for the ticket. Important: some carriers do not accept electronic tickets—only printed ones. This limitation must be explicitly shown in the UI before purchase, otherwise you'll get a wave of negative reviews.

The QR is stored in FileManager (iOS) or filesDir (Android) for offline access. Push notification 2 hours before departure via FCM/APNs.

How Is Offline Access to Tickets Ensured?

We cache QR codes and ticket data locally so passengers can present tickets without internet. We use FileManager (iOS) or filesDir (Android) with encryption. The ticket list syncs on each network connection, and delay/cancellation notifications arrive via push services.

Payment

SBP is the main payment method for bus tickets: low commission (0.4–0.7%), instant settlement. YooKassa or CloudPayments for cards. Apple Pay and Google Pay increase conversion at the final step—we don't forget them.

For some carriers, cash payment upon boarding is required: booking without payment with a 30-minute hold. No need for hold scheme; a flag payment_method: cash in the booking suffices.

Ticket Refunds

Refunds via the carrier or aggregator API. Conditions vary by carrier—we display them on the purchase screen, not hidden in the terms of service. Technically: DELETE /orders/{id} or POST /orders/{id}/refund. Money is returned to the card within 3–10 business days depending on the bank.

Typical policy: free cancellation 3+ hours before departure, 10–30% penalty for cancellation less than 3 hours before. Specific conditions come from the API along with the schedule.

Notifications and Tracking

Delay tracking—via carrier API if supported, or by polling flight status every 5 minutes. Push 2 hours and 30 minutes before departure. If the carrier supports GPS tracking, we show the current bus location on the map via MapKit or Google Maps SDK.

What’s Included in the Work

• Integration documentation (API description, data schemas, request examples).
• Access to test API (sandbox) for debugging.
• Training of carrier personnel on app usage.
• Support during App Store and Google Play release.
• Warranty for fixing critical errors within 30 days after delivery.
• Source code and app ownership (you get full ownership).

Timeline

4–6 weeks for an app for a specific carrier or with an aggregator API. Cost is calculated individually after requirements analysis. Order turnkey development—contact us for a preliminary estimate. Proper integration with data sources reduces time to market by up to 30%.

Get a consultation on your project—we will help you choose the optimal integration path.

Payments in Mobile Apps: In-App Purchase, StoreKit 2, Google Billing, Stripe, RevenueCat

In every monetization project, we balance App Store and Google Play policies, PCI DSS requirements, and purchase verification logic on the backend. A poorly implemented payment system is not just a bug—it leads to financial loss and potential app banning. Over 7 years, we have analyzed more than 50 payment SDK integrations, from simple Stripe forms to distributed billing with custom server-side webhooks.

In-App Purchase: Two Platforms, Two Different APIs

If your app sells digital content or subscriptions, Apple and Google require you to use their payment systems. This is non-negotiable: violating App Store rule 3.1.1 or Google Play Developer Policy results in app removal. Physical goods and offline services are a different story.

StoreKit 2 (iOS 15+)

StoreKit 2 is a complete overhaul of the original StoreKit with async/await API. Product.products(for:), product.purchase(), Transaction.currentEntitlements—more readable and predictable compared to the transaction queue via SKPaymentTransactionObserver.

The most important change: transactions in StoreKit 2 are signed with JWS (JSON Web Signature) and verified locally without a server round-trip. Transaction.verificationResult returns .verified(Transaction) or .unverified(Transaction, VerificationError). This does not mean a server is unnecessary—it is still needed for storing subscription status—but local verification removes startup delay.

StoreKit.AppTransaction verifies the actual app download from the App Store. Required for paid downloads or non-renewing purchases.

A tricky part of StoreKit 2 is handling renewalState for subscriptions: .subscribed, .expired, .inBillingRetryPeriod, .inGracePeriod, .revoked. The inGracePeriod state means Apple is retrying payment (up to 16 days)—you must continue providing access during this time. Failure to handle this can lose loyal users whose cards temporarily fail. Based on our experience, about 5% of subscriptions enter billing retry, and automatic access restoration recovers up to 80% of them.

Google Play Billing Library (v6+)

Google Billing is more complex than StoreKit in terms of scenario handling. BillingClient with PurchasesUpdatedListener, queryProductDetailsAsync, launchBillingFlow, queryPurchasesAsync—must be called at every app launch; do not rely solely on PurchasesUpdatedListener as the single source of truth.

Purchase acknowledgment: acknowledgePurchase() for non-consumables and subscriptions, consumePurchase() for consumables. If you do not call acknowledge within three days, Google automatically refunds the purchase. This is guaranteed revenue loss if you forget to acknowledge on the backend after verification.

ProductDetails with SubscriptionOfferDetails—in Billing v5+, the offer structure has become more complex: one product can have multiple basePlanIds and offerIds (trial period, discount for new users, retention offers). BillingFlowParams.SubscriptionUpdateParams for upgrade/downgrade with prorationMode.

Why Is Server-Side Verification Mandatory?

Never trust only client-side code when unlocking paid content. Client-side verification can be bypassed by modifying the app.

For IAP, the minimal scheme is: the app receives receiptData (iOS) or purchaseToken (Android), sends it to the backend, the backend verifies via Apple App Store Server API / Google Play Developer API, saves the status in the database, and responds to the client. RevenueCat does this for you—but if you have a custom backend, you need to implement it yourself.

Webhooks are more important than they seem. Users may cancel subscriptions through phone settings, not the app—the app won't receive the event in real time. Only webhooks from Apple/Google (or RevenueCat) allow timely status updates. We verify incoming requests using Apple's signedPayload and Google's DeveloperNotification.

How Does RevenueCat Simplify Integration?

Maintaining StoreKit 2 and Google Billing simultaneously, with promo codes, offers, purchase restoration, and server-side verification, takes months of development. RevenueCat handles most of this layer.

RevenueCat is not just a payment SDK. It offers:

• A unified API for iOS and Android (and Stripe for web)
• Server-side verification and subscription status storage
• Webhooks for events (purchase, renewal, cancellation, billing issue)
• Analytics for cohorts, MRR, churn
• A/B testing of offers via Experiments

Purchases.configure(withAPIKey:) at startup, Purchases.shared.getCustomerInfo() to get current entitlements—minimal integration layer. Purchases.shared.purchase(package:) instead of directly calling StoreKit/Billing.

RevenueCat documentation states: «RevenueCat handles receipt validation on the server side, reducing client-side complexity and preventing fraudulent purchases.»

Limitations of RevenueCat: it is paid (free up to $2.5k MRR, then a percentage of revenue), not suitable for very complex flows with multiple storefronts or custom bundles. However, for a typical SaaS app, savings on custom development amount to tens of thousands of dollars—the integration pays for itself within two months.

Stripe in Mobile Apps

Stripe is used for physical goods, services, and B2B payments where IAP is not required by platform policy.

Stripe iOS SDK and Android SDK—PaymentSheet for ready-made payment UI, PaymentSheetFlowController for custom UI with saved cards. Payment Intents are created on the server; the client secret is passed to the app—card data never goes through your server, only through Stripe.

Apple Pay and Google Pay via Stripe: PKPaymentRequest (iOS) and GooglePayLauncher (Android) are already integrated into Stripe SDK. Apple Pay conversion rates are 1.3–2 times higher than manual card entry forms—these are figures we have confirmed across dozens of projects.

Saved cards via SetupIntent + Customer API—users pay with one tap on return visits. Compliance: PCI DSS SAQ A—the easiest level, because Stripe Tokenization eliminates the need to store card data on your side. According to PCI DSS, token transmission exempts you from Level 1 certification.

3DS2 (Strong Customer Authentication) is mandatory for payments in the EU under PSD2. Stripe handles it automatically via PaymentIntent.confirmPayment, but you need to correctly handle the .requiresAction status and return the user to the appropriate screen after authentication.

What Is Included in the Work (Deliverables)

Process and Timeline

We start by clarifying the business model: subscriptions, one-time purchases, consumables, freemium. The architecture depends on this. Testing IAP requires Sandbox accounts (Apple) and License Testers (Google)—this is a separate environment setup.

Apple's Sandbox behaves differently from production: subscriptions renew every 5 minutes instead of monthly, inGracePeriod works differently. It is essential to test scenarios: trial expiration, cancellation, billing retry, refund.

The cost is calculated individually based on the set of tools and complexity of server-side logic. On average, we fit within a budget for a typical integration, but the savings from preventing errors and churn offset this investment within a few months.

Get a consultation for your project—contact us. We will help you choose the optimal payment architecture that passes store reviews and does not break under peak loads.