How to Write a PRD for a Mobile App
Mobile app PRDs must address constraints web PRDs never encounter: platform-specific guidelines, offline functionality, device diversity, app store reviews, and cellular network performance.
This guide covers mobile-specific PRD sections beyond standard product requirements.
Step-by-step guide
Define Platform Strategy
Decide iOS-first, Android-first, or cross-platform. Consider target audience device distribution, team skills, and budget. Starting with one platform is usually faster than both simultaneously.
- Analyze target audience device split
- Choose development approach (native, cross-platform, hybrid)
- Define feature parity strategy
- Include platform design guidelines (HIG, Material Design)
Specify Offline Behavior
Define what works without internet. Mobile users lose connectivity in elevators, subways, and rural areas. Specify cached features, data sync strategy, conflict resolution on reconnection, and offline UX states.
- List offline vs online-only features
- Define caching strategy and duration
- Specify conflict resolution for offline edits
- Design offline state UX indicators
Set Performance Budgets
Define targets for mid-range devices on cellular: cold start under 2 seconds, app size budget, memory limits, and battery consumption. Measure on real devices, not simulators.
- Set cold start target for mid-range devices
- Define app size budget
- Specify memory usage limits
- Include battery consumption targets
Design for Device Diversity
Cover screen sizes, OS versions, hardware capabilities, and accessibility. Define minimum OS, testing device matrix, and handling for notches, foldables, and landscape mode.
- Set minimum OS version
- Define testing device matrix
- Specify responsive layout rules
- Include accessibility requirements
Plan App Store Compliance
Document privacy labels, data disclosures, IAP requirements, and content ratings. App store review takes 1-7 days; rejection requires resubmission. Build this into timelines.
- Document App Store Review Guidelines compliance
- Prepare Google Play data safety content
- Identify IAP requirements
- Plan review timeline into release schedule
Define Push Notification Strategy
Specify trigger events, opt-in flow, content format, frequency limits, and preference management. Push notifications drive engagement but also drive uninstalls if misused.
- List notification types with triggers
- Design permission request flow (not on first launch)
- Set frequency limits per type
- Include preference management in settings
Specify Privacy and Permissions
Document every device permission needed (camera, location, contacts) with the specific feature requiring it and user-facing explanation. Both platforms require clear purpose strings.
- List every required permission with purpose
- Write user-facing permission explanations
- Define data retention policies
- Plan graceful degradation when permissions denied
Common mistakes
Testing Only on WiFi
Most users are on cellular with variable bandwidth. Test on 3G/4G conditions. Optimize image loading and API payloads for constrained networks.
Ignoring App Size
App size affects downloads, especially in storage-constrained markets. Apple warns about 200MB+ cellular downloads. Track size in CI/CD.
Requesting All Permissions at Launch
Blanket permission requests on first launch cause denials. Request each permission contextually when the feature is first used.
Tips
Test on mid-range devices and cellular, not flagships on WiFi
Offline behavior is a feature, not an edge case
Track app size in CI/CD with alerts when budget exceeded
Request permissions contextually, not at launch
How Vantage helps
Vantage generates PRDs that include mobile-specific requirements for platform strategy, performance budgets, and compliance based on context you provide about target platforms.