Flutter / iOS / Android Subscription Expert Needed – Investigation & Root Cause Analysis
Budget: $30 – $250 USD
I am looking for an experienced Flutter developer with strong knowledge of Apple App Store subscriptions, Google Play Billing, receipt validation, and backend integration.
This is Phase 1 of the project.
The goal is NOT to immediately fix everything. The initial objective is to investigate the existing implementation, identify the root causes of the subscription issues, and provide a clear plan for resolving them. If the investigation is successful, there is a high likelihood of continuing with the same developer for the implementation phase.
Background
Our mobile app is built with Flutter and connects to a SkaDate (PHP/MySQL) backend.
We have been experiencing subscription synchronization issues affecting both iOS and Android. Previous work has improved several areas, but important production issues remain.
Current Issues
1. iOS Subscription Synchronization
Some users successfully purchase a monthly VIP subscription through the Apple App Store.
Apple confirms the payment, and the subscription appears as active in the user's Apple account.
However:
The user's account remains FREE.
No payment is recorded in /admin/finance.
VIP features are not activated.
This has occurred with multiple production users.
2. Android Duplicate Transactions
Occasionally, an Android purchase is recorded twice in /admin/finance.
The duplicate entries contain:
The exact same Google Play transaction ID
Same user
Same timestamp
Same amount
The user appears to be charged only once, but the backend records the transaction twice.
Phase 1 Deliverables
The selected freelancer will:
Review the Flutter purchase implementation.
Review the backend subscription validation process.
Review the communication between the mobile apps and the backend.
Identify the root cause of the iOS synchronization issue.
Identify the root cause of the Android duplicate transaction issue.
Explain what needs to be changed.
Fix any obvious issues discovered during the investigation if appropriate.
Provide a written summary of findings and recommended solutions.
If we are satisfied with the investigation, we intend to continue with the same developer for Phase 2 (implementation and testing).
Required Experience
Please apply only if you have experience with:
Flutter
Apple StoreKit / In-App Purchases
Google Play Billing
Receipt validation
PHP backend integration
REST APIs
Production debugging
Experience with SkaDate is a plus but not required.
Access Provided
We have a staging environment available that is an exact private replica of the live TransSingle website.
The staging environment is used for testing changes before applying them to production.
The selected developer will be able to use the staging environment to:
Review and test subscription-related changes safely.
Debug issues without affecting live users.
Validate fixes before deployment to production.
The selected developer will receive access to:
Flutter source code
Backend/API source code
Test accounts
Apple App Store Connect (if needed)
Google Play Console (if needed)
Server logs
When Applying
Please include:
Examples of similar subscription or in-app purchase issues you have solved.
Your experience with Flutter subscription systems.
A brief explanation of how you would investigate these issues.
Your estimated time for the investigation phase.
This project involves a production application with paying customers, so I am looking for someone with proven experience diagnosing and resolving mobile subscription issues.
This is Phase 1 of the project.
The goal is NOT to immediately fix everything. The initial objective is to investigate the existing implementation, identify the root causes of the subscription issues, and provide a clear plan for resolving them. If the investigation is successful, there is a high likelihood of continuing with the same developer for the implementation phase.
Background
Our mobile app is built with Flutter and connects to a SkaDate (PHP/MySQL) backend.
We have been experiencing subscription synchronization issues affecting both iOS and Android. Previous work has improved several areas, but important production issues remain.
Current Issues
1. iOS Subscription Synchronization
Some users successfully purchase a monthly VIP subscription through the Apple App Store.
Apple confirms the payment, and the subscription appears as active in the user's Apple account.
However:
The user's account remains FREE.
No payment is recorded in /admin/finance.
VIP features are not activated.
This has occurred with multiple production users.
2. Android Duplicate Transactions
Occasionally, an Android purchase is recorded twice in /admin/finance.
The duplicate entries contain:
The exact same Google Play transaction ID
Same user
Same timestamp
Same amount
The user appears to be charged only once, but the backend records the transaction twice.
Phase 1 Deliverables
The selected freelancer will:
Review the Flutter purchase implementation.
Review the backend subscription validation process.
Review the communication between the mobile apps and the backend.
Identify the root cause of the iOS synchronization issue.
Identify the root cause of the Android duplicate transaction issue.
Explain what needs to be changed.
Fix any obvious issues discovered during the investigation if appropriate.
Provide a written summary of findings and recommended solutions.
If we are satisfied with the investigation, we intend to continue with the same developer for Phase 2 (implementation and testing).
Required Experience
Please apply only if you have experience with:
Flutter
Apple StoreKit / In-App Purchases
Google Play Billing
Receipt validation
PHP backend integration
REST APIs
Production debugging
Experience with SkaDate is a plus but not required.
Access Provided
We have a staging environment available that is an exact private replica of the live TransSingle website.
The staging environment is used for testing changes before applying them to production.
The selected developer will be able to use the staging environment to:
Review and test subscription-related changes safely.
Debug issues without affecting live users.
Validate fixes before deployment to production.
The selected developer will receive access to:
Flutter source code
Backend/API source code
Test accounts
Apple App Store Connect (if needed)
Google Play Console (if needed)
Server logs
When Applying
Please include:
Examples of similar subscription or in-app purchase issues you have solved.
Your experience with Flutter subscription systems.
A brief explanation of how you would investigate these issues.
Your estimated time for the investigation phase.
This project involves a production application with paying customers, so I am looking for someone with proven experience diagnosing and resolving mobile subscription issues.