Build Cross-Platform Apps: One Codebase for iOS, Android, and Web in 2025

The Cross-Platform Promise: Build Once, Deploy Everywhere

Imagine building your app once and having it work perfectly on:

• ✅ iPhone and iPad (iOS App Store)
• ✅ Android phones and tablets (Google Play Store)
• ✅ Web browsers (any device)
• ✅ Telegram (1 billion+ users)

No separate iOS team, Android team, and web team. No maintaining three different codebases. No fixing the same bug three times.

Just one project. One build process. Multiple platforms.

This is the promise of cross-platform development—and in 2025, it's not just a promise. It's reality.

This guide explains how cross-platform development works, why it's perfect for most apps, and how to build cross-platform apps without coding using modern no-code platforms like AppStruct.

What You'll Learn

• ✅ What cross-platform development means (and misconceptions)
• ✅ Native vs cross-platform: honest comparison
• ✅ How to build cross-platform apps without coding
• ✅ Platform-specific considerations (iOS, Android, Web, Telegram)
• ✅ Performance and UX optimization
• ✅ Real examples and cost comparisons
• ✅ When cross-platform is the smart choice (usually)

Reading time: 16 minutes
Potential savings: $80,000-200,000+ (vs building separately for each platform)

Part 1: Understanding Cross-Platform Development

What Is Cross-Platform Development?

Traditional approach (separate native apps):

iOS App:
  Written in Swift/Objective-C
  iOS-specific design
  iOS-specific features
  Published to App Store

Android App:
  Written in Kotlin/Java (completely different)
  Android-specific design
  Android-specific features
  Published to Google Play

Web App:
  Written in JavaScript/React/etc (also different)
  Responsive web design
  Browser-specific considerations
  Hosted on web server

Result: 3 separate codebases, 3 development teams, 3x the cost

Cross-platform approach:

One Project:
  Visual development (no code) OR single codebase (if coding)
  Adaptive design (works on all platforms)
  Platform features (access to each platform's capabilities)

Publish to:
  → iOS App Store (native iOS app)
  → Google Play Store (native Android app)
  → Web (Progressive Web App)
  → Telegram (Mini App)

Result: 1 project, 1 development process, 1x cost

Cross-Platform Myths Debunked

❌ Myth: "Cross-platform apps are slow"
✅ Reality: Modern cross-platform frameworks compile to native code. Performance is virtually identical to native apps for 95% of use cases.

❌ Myth: "Can't access platform-specific features"
✅ Reality: Cross-platform tools provide access to camera, GPS, notifications, biometrics, and most native features.

❌ Myth: "Apps look generic, not native"
✅ Reality: Good cross-platform development adapts UI to each platform. iOS version looks iOS-native, Android looks Android-native.

❌ Myth: "You're limited to simple apps"
✅ Reality: Complex apps like Instagram, Uber Eats, and major SaaS products use cross-platform development.

❌ Myth: "Eventually need to rebuild natively"
✅ Reality: Most apps never outgrow cross-platform. The few that do are usually in top 0.1% (think Instagram-scale).

Cross-Platform vs Native: Honest Comparison

Cross-platform wins for: 95% of apps
Native required for: less than 5% (advanced games, AR/VR, specific hardware integration)

Part 2: Cross-Platform with No-Code

Why No-Code is Perfect for Cross-Platform

Traditional cross-platform frameworks:

• React Native (requires JavaScript knowledge)
• Flutter (requires Dart knowledge)
• Xamarin (requires C# knowledge)

Still requires coding even if "easier" than separate native development.

No-code cross-platform (AppStruct):

• ✅ Zero coding required
• ✅ Visual development for all platforms
• ✅ Same interface for iOS, Android, Web
• ✅ Platform-specific optimizations automatic
• ✅ Deploy to all platforms from one project

How AppStruct Enables True Cross-Platform

Build Once:

1. Design your app visually
2. Add components (buttons, forms, lists, etc.)
3. Connect to database
4. Configure workflows
5. Style and brand

Deploy Everywhere:

1. Click "Publishing"
2. Select platforms:
   • ✅ Web App (PWA)
   • ✅ iOS App Store (requires Premium plan)
   • ✅ Google Play Store (requires Premium plan)
   • ✅ Telegram Mini App (requires Premium plan)
3. Configure platform-specific settings
4. Publish

Your one project now reaches:

• iOS users
• Android users
• Web users (any device/browser)
• Telegram users (1 billion+)

Platform-Specific Optimizations

AppStruct automatically adapts:

iOS Version:

• iOS-style navigation (back button, tab bar)
• iOS gestures (swipe back)
• iOS fonts and spacing
• iOS-specific features (Face ID, etc.)
• Follows Apple Human Interface Guidelines

Android Version:

• Material Design components
• Android navigation patterns
• Android gestures
• Android-specific features (back button handling)
• Follows Google Material Design

Web Version:

• Responsive design (mobile, tablet, desktop)
• Browser-optimized interactions
• SEO-friendly
• Accessible via URL
• Works offline (PWA)

Telegram Version:

• Telegram-native UI patterns
• Bot integration
• Telegram payments
• No download required
• Instant access

You design once, AppStruct adapts for each platform.

Part 3: Building Cross-Platform Apps

Phase 1: Design for All Platforms

Mobile-First Responsive Design:

Start with Mobile (320-428px width):

• Smallest screen size
• Touch-friendly interactions
• Bottom navigation (thumb-friendly)
• Vertical scrolling

Scale to Tablet (768-1024px):

• More screen real estate
• Two-column layouts
• Side navigation appears
• Larger touch targets still

Expand to Desktop (1024px+):

• Multi-column layouts
• Keyboard shortcuts
• Mouse hover states
• Sidebar navigation

In AppStruct:

• Design for mobile viewport first
• Add breakpoints for tablet/desktop
• Components adapt automatically
• Preview on all sizes

Phase 2: Platform-Specific Features

Leverage Platform Strengths:

iOS-Specific:

• Face ID / Touch ID authentication
• Apple Pay integration
• iOS Share Sheet
• Siri Shortcuts
• Haptic feedback (vibration patterns)

Android-Specific:

• Google Pay
• Android Share
• NFC capabilities
• Widgets (home screen)
• Custom notifications

Web-Specific:

• SEO optimization
• Deep linking (URL-based)
• Browser extensions
• Desktop shortcuts
• Keyboard navigation

Telegram-Specific:

• Bot integration
• Telegram Stars payments
• In-chat sharing
• No download required
• Free push notifications

AppStruct provides access to platform features through visual interface—no platform-specific coding.

Phase 3: Database and Backend

Single Backend for All Platforms:

AppStruct's PostgreSQL Database:

• Same database serves all platforms
• Real-time sync across platforms
• User logs in on iPhone, data available on web
• Start task on Android, finish on desktop

Multi-Platform Authentication:

• User creates account on any platform
• Login works across all platforms
• Session sync (logged in everywhere)
• Security maintained

Example User Journey:

Monday morning:
  - Opens app on iPhone
  - Creates project
  - Adds 3 tasks

Monday afternoon:
  - Opens web version on desktop
  - Sees same projects and tasks
  - Adds more details
  - Invites team member

Tuesday:
  - Team member gets notification on Android
  - Opens app
  - Completes task
  - Everyone sees update instantly

All from one AppStruct project.

Part 4: Publishing to Multiple Platforms

iOS App Store Publishing

Requirements:

• Apple Developer Account ($99/year)
• AppStruct Premium plan
• App Store assets (icon, screenshots, description)

Process:

1. Prepare app metadata in AppStruct
2. Generate iOS build (AppStruct handles code signing)
3. Submit to App Review
4. Wait 1-3 days for review
5. App goes live on App Store

AppStruct handles:

• Native iOS app generation
• Certificates and provisioning
• Build optimization
• App Store compliance

Guide to iOS publishing →

Google Play Store Publishing

Requirements:

• Google Play Developer Account ($25 one-time)
• AppStruct Premium plan
• Play Store assets (icon, screenshots, description)

Process:

1. Prepare app metadata
2. Generate Android build (AppStruct creates AAB file)
3. Upload to Play Console
4. Submit for review
5. Live in few hours to 1 day

AppStruct handles:

• Native Android app generation
• App signing
• Optimization
• Play Store requirements

Guide to Android publishing →

Web App Publishing

Requirements:

• Domain (optional, can use subdomain)
• AppStruct (any plan—Free tier works!)

Process:

1. Click "Publishing" → "Web App"
2. Configure domain
3. Click "Publish"
4. Live immediately

AppStruct provides:

• HTTPS/SSL automatic
• Global CDN
• PWA manifest
• Offline capabilities
• SEO optimization

Telegram Mini App Publishing

Requirements:

• Telegram bot (free to create)
• AppStruct Premium plan

Process:

1. Create bot via @BotFather
2. Configure in AppStruct
3. Publish Telegram version
4. Share bot link
5. Live instantly (no review)

Telegram Mini App guide →

Part 5: Cost Comparison

Building Separately vs Cross-Platform

Scenario: Medium-Complexity App (Booking System)

Separate Native Development:

iOS App:
  Development: $50,000
  Timeline: 3 months

Android App:
  Development: $50,000
  Timeline: 3 months

Web App:
  Development: $30,000
  Timeline: 2 months

Total: $130,000, 8 months
(Assuming parallel development with 3 teams)

Cross-Platform with AppStruct:

All Platforms:
  AppStruct subscription: $900/year
  Build yourself: 4-6 weeks
  OR hire no-code dev: $8,000-12,000

Total: $900-12,900, 4-6 weeks

Savings: $118,000-129,000 (91-99%)
Time savings: 5-6 months

Ongoing Maintenance Costs

Separate Native:

iOS maintenance: $8,000/year
Android maintenance: $8,000/year
Web maintenance: $5,000/year
Updates across platforms: $10,000/year
Total: $31,000/year

Cross-Platform:

AppStruct: $900/year
Updates: $0 (do yourself) or $1,000/year (if hiring)
Total: $900-1,900/year

Annual savings: $29,000-30,000

5-year total cost:

Separate native: $130,000 + ($31,000 × 5) = $285,000
Cross-platform: $12,900 + ($1,900 × 5) = $22,400

5-year savings: $262,600 (92%)

Part 6: Platform Considerations

iOS Platform Specifics

What Makes iOS Unique:

• Premium user base (higher revenue per user)
• Strict app review process (1-3 days)
• Design guidelines (iOS Human Interface Guidelines)
• 30% App Store commission on in-app purchases
• Privacy-focused (permissions prominently displayed)

Cross-Platform Advantages for iOS:

• Launch faster (no learning Swift)
• Update across platforms simultaneously
• Web version bypasses App Store (instant updates)
• Maintain consistent design

iOS Testing Critical:

• Test on actual iPhones (not just simulator)
• Test on different iOS versions (iOS 15, 16, 17)
• iPad layout if supporting tablets
• Dark mode appearance

Android Platform Specifics

What Makes Android Unique:

• Larger global user base
• More device variety (hundreds of models)
• Faster app review (hours to 1 day)
• More flexible policies
• Dominant in emerging markets

Cross-Platform Advantages for Android:

• Handles device fragmentation automatically
• Consistent experience across devices
• Easier testing (web version close to Android behavior)

Android Testing:

• Test on popular models (Samsung, Google Pixel)
• Different screen sizes and resolutions
• Various Android versions
• Performance on lower-end devices

Web Platform Specifics

What Makes Web Unique:

• No download required (instant access)
• SEO benefits (Google can find you)
• Works on any device with browser
• Updates instant (no app store approval)
• Shareable via URL

Cross-Platform Advantages for Web:

• Same functionality as mobile apps
• Desktop users get full experience
• Marketing leads here first
• Can A/B test before app store launch

Web Optimization:

• Fast loading (under 3 seconds)
• Mobile responsive
• Browser compatibility (Chrome, Safari, Firefox, Edge)
• Progressive Web App features (installable)

Telegram Platform Specifics

What Makes Telegram Unique:

• No download (opens in Telegram)
• Built-in payment (Telegram Stars)
• Free notifications (message users)
• 1 billion+ potential users
• Popular in Russia, LATAM, parts of EU

Cross-Platform Advantage:

• Your web/mobile app can also be Telegram app
• Reach users who won't download apps
• Zero friction entry
• Free marketing via Telegram channels

Complete Telegram Mini App guide →

Part 7: User Experience Across Platforms

Adaptive Design Patterns

Navigation:

Mobile (iOS/Android):

• Bottom tab bar (main sections)
• Top navigation bar (page title, back)
• Hamburger menu (secondary features)
• Gestures (swipe, pull to refresh)

Desktop/Web:

• Side navigation (always visible)
• Top menu bar
• Keyboard shortcuts
• Mouse hover states

Telegram:

• Compact design (opens in chat)
• Bottom buttons (Telegram style)
• Back to chat functionality

AppStruct adapts automatically based on platform and screen size.

Touch vs Mouse Interactions

Mobile Design (Touch):

• Larger touch targets (min 44×44px)
• Swipe gestures
• Long-press actions
• Pull to refresh
• No hover states

Desktop Design (Mouse):

• Smaller clickable areas OK
• Hover tooltips
• Right-click menus
• Drag and drop
• Keyboard shortcuts

Both in AppStruct:

• Design for touch first
• Hover states added automatically for desktop
• Interactions adapt to input method

Platform-Specific UI Elements

iOS Elements:

• Rounded buttons
• Bottom tab bar
• Segmented controls
• Action sheets
• iOS-style switches

Android Elements:

• Material Design buttons
• Navigation drawer
• Floating action button
• Bottom sheets
• Android-style switches

Web Elements:

• Standard web forms
• Dropdown menus
• Breadcrumbs
• Pagination
• Desktop-optimized layouts

AppStruct's component library includes platform-adaptive elements that automatically look native on each platform.

Part 8: Building Cross-Platform Apps with AppStruct

Step 1: Create Cross-Platform Project

1. Sign in to AppStruct
2. Create new project
3. Select "Cross-Platform App"
4. Choose starting template (or blank)

What you get:

• Project configured for all platforms
• Responsive breakpoints set up
• Platform detection enabled
• Adaptive components ready

Step 2: Design Responsively

Use AppStruct's Layout System:

1. Mobile Layout (Base)

• Design for 375px width (iPhone)
• Stack elements vertically
• Single-column layout
• Bottom navigation

2. Tablet Layout (Breakpoint)

• Triggers at 768px width
• Two-column layouts
• Side navigation appears
• More content visible

3. Desktop Layout (Breakpoint)

• Triggers at 1024px width
• Multi-column layouts
• Full sidebar navigation
• Keyboard-friendly

Visual Breakpoint Editor:

• Drag handle to set breakpoints
• See layout at each size
• Adjust component behavior
• Test responsiveness

Step 3: Platform-Specific Logic

Conditional Features:

Example: Different payment for each platform

If platform = iOS:
  Use: In-App Purchase (Apple requirement)

If platform = Android:
  Use: Google Play Billing OR Stripe

If platform = Web:
  Use: Stripe (no app store restrictions)

If platform = Telegram:
  Use: Telegram Stars OR Stripe

AppStruct's platform detection:

• Automatically knows which platform
• Show/hide features per platform
• Adapt behavior accordingly

Step 4: Test on All Platforms

Testing Workflow:

iOS Testing:

1. AppStruct preview on iPhone
2. Install test build via TestFlight
3. Test on iOS 16 and iOS 17
4. Check iPad if supporting tablets

Android Testing:

1. Preview on Android device
2. Install APK test build
3. Test on different manufacturers (Samsung, Google Pixel, etc.)
4. Various Android versions

Web Testing:

1. Chrome, Safari, Firefox, Edge
2. Mobile browsers (Chrome mobile, Safari mobile)
3. Different screen sizes (responsive)
4. Lighthouse audit (performance, SEO)

Telegram Testing:

1. Open in Telegram
2. Test bot integration
3. Test payments (Telegram Stars)
4. Check iOS and Android Telegram clients

AppStruct provides:

• One-click preview on any platform
• Test builds generation
• Device emulation
• Remote testing tools

Step 5: Publish to All Platforms

Publishing Checklist:

• App icon designed (1024×1024px, works on all platforms)
• Screenshots for each platform (iOS, Android, Web)
• App description written
• Keywords researched (ASO for iOS/Android)
• Privacy policy published
• Terms of service published
• Support email/contact set up

AppStruct Publishing:

• Select all target platforms
• Configure each (uses shared content)
• Submit to iOS (1-3 day review)
• Submit to Android (few hours review)
• Publish Web (instant)
• Publish Telegram (instant)

Result: Your app live on all platforms within a week.

Part 9: Real Cross-Platform Success Stories

Case Study 1: Fitness App (Global)

App: Workout tracker with social features

Platforms:

• iOS (primary, 60% of users)
• Android (35% of users)
• Web (5%, mainly desktop trainers)

Built with: AppStruct

Development:

• Timeline: 6 weeks
• Cost: $12,000 (hired no-code developer)
• Team: Founder (non-technical) + 1 no-code dev

Results (18 months):

• 45,000 iOS downloads
• 28,000 Android downloads
• 3,000 web users
• $23/month average subscription
• MRR: $52,000

Key insight: "70% of our users came through web (SEO). They then downloaded mobile apps. Cross-platform was essential—we couldn't have afforded separate development."

Case Study 2: Local Services Marketplace (EU)

App: Connect homeowners with service providers (cleaning, repair, etc.)

Platforms:

• Web (primary for booking)
• iOS (customer convenience)
• Android (majority of service providers)

Built with: AppStruct

Development:

• Timeline: 10 weeks
• Cost: €900/year (DIY by founder)
• Founder: Former teacher, zero coding

Results (2 years):

• 180 service providers
• 3,200 customers
• 15% commission model
• €45,000 monthly GMV
• Monthly revenue: €6,750

Key insight: "Service providers use Android (70%). Customers use mix. Web is where people discover us (SEO). We needed all platforms to work."

Case Study 3: Education Platform (LATAM)

App: Online courses for professional development

Platforms:

• Web (primary for course viewing)
• Android (dominant in region)
• Telegram (growing channel)

Built with: AppStruct

Development:

• Timeline: 8 weeks
• Cost: $900/year +$3,000 (hired help for complex parts)
• Languages: Spanish and Portuguese

Results (14 months):

• 2,800 students enrolled
• 45 courses offered
• $25/month average subscription
• MRR: $17,500
• 40% students from Telegram (unique channel)

Key insight: "Telegram Mini App was game-changer for LATAM. Many students couldn't download apps (storage) or didn't want to. Telegram has zero friction."

Part 10: Cross-Platform Best Practices

Design Best Practices

1. Design System Consistency

• Use consistent colors across platforms
• Same fonts (but respect platform defaults)
• Consistent spacing and sizing
• Unified brand experience

2. Respect Platform Patterns

• iOS back button (top left)
• Android back button (bottom/gesture)
• Web breadcrumbs
• Platform-familiar icons

3. Adaptive Layouts

• Single column on mobile
• Two column on tablet
• Three+ column on desktop
• Optimize for each

4. Touch-Friendly Everywhere

• Even on desktop, some users have touchscreens
• Touch targets 44×44px minimum
• Adequate spacing
• No tiny click areas

Development Best Practices

1. Test on Real Devices

• Don't rely only on preview/emulator
• Test on actual iPhones and Android phones
• Check desktop browsers
• Validate on Telegram

2. Handle Platform Differences Gracefully

Feature available on some platforms only:
  - Show on supported platforms
  - Hide on unsupported
  - Or show "Available on iOS app" with download link

3. Optimize Assets for Each Platform

• Image sizes appropriate for device
• Video formats compatible
• Font loading optimized
• Platform-specific icons

4. Unified Update Strategy

Plan feature:
  - Develop for all platforms simultaneously
  - Test on all platforms
  - Deploy to all platforms together
  - Consistent release schedule

Performance Best Practices

1. Lazy Loading

• Load content as needed
• Don't load entire database on startup
• Paginate long lists
• Progressive image loading

2. Caching Strategy

• Cache frequently accessed data
• Offline access to critical content
• Sync in background
• Clear cache strategically

3. Network Optimization

• Compress API responses
• Batch requests where possible
• Handle offline gracefully
• Show loading states

4. Platform-Specific Optimization

• iOS: Optimize for slower devices (iPhone SE, etc.)
• Android: Test on budget devices
• Web: Optimize for mobile data (compress)
• Telegram: Fast load critical (competes with native)

AppStruct handles most optimization automatically.

Conclusion: Cross-Platform is the Default Choice

In 2024, the question isn't "Should I build cross-platform?"
It's "Is there a specific reason I need separate native apps?"

For 95% of apps, the answer is no.

Cross-platform with no-code offers:

• ✅ 85-99% cost savings
• ✅ 4-6x faster development
• ✅ Reach 100% of potential users (all platforms)
• ✅ One codebase to maintain
• ✅ Simultaneous updates
• ✅ Consistent user experience
• ✅ No coding required

The only apps that truly need separate native development:

• Advanced 3D games
• AR/VR experiences
• Apps with exotic hardware integration
• Top 0.1% apps with massive scale

Everyone else should default to cross-platform.

Start Building Cross-Platform Today

Your path to multi-platform success:

1. Create free AppStruct account
2. Build your app once (visually, no code)
3. Test on all platforms
4. Publish everywhere simultaneously
5. Reach maximum audience

Timeline: 2-8 weeks from start to all platforms live
Cost: $540-900/year (vs$130K+ for separate development)

Ready to reach users on every platform?

Start building cross-platform now →

Questions about cross-platform development?

• Documentation
• Templates
• Email: support@appstruct.cloud

Related Cross-Platform Articles

• How to Build Mobile App Without Code
• Progressive Web Apps Guide
• Telegram Mini Apps Guide
• No-Code App Development Guide

Last updated: October 2025 | Reading time: 16 minutes | Cross-platform development guide