Use App Tester when you're in the thick of development and need fast feedback loops. It responds to your app's IAP API calls using mock data stored in a local JSON file, letting you control exactly what purchase responses your app receives. This makes it perfect for testing edge cases and error scenarios.

Since everything runs locally with predetermined responses, you get rapid iteration cycles. No waiting for network calls or dealing with service downtime. Just focus on whether your code processes IAP events correctly.
 

Setting up App Tester

Getting App Tester running is straightforward. Detailed instructions can be found here. Here is a quick highlight of the key steps:

1. Connect your computer to your device through adb.

2. Set your app to use sandbox mode, using adb shell setprop.

3. Copy the JSON file with your IAP to your device.
Follow the instructions here for information about formatting and where to store it on your device.

4. Install App Tester through the Amazon Appstore.

Use DevTest for IAP when you need to test complex flows—like subscription management, product catalog integrations, or purchase restoration—that require real Amazon services.

DevTest works with your existing IAP implementation without code changes. It simply routes your Appstore SDK API calls to Amazon's testing servers instead of production.

DevTest handles scenarios that mock responses can't fully replicate, like testing across different device configurations and user account states, all while maintaining fast iteration cycles without app submission overhead.
 

Setting up DevTest

DevTest setup focuses on registration and tester management rather than code integration. Here are the key steps from the official workflow:

1. Generate a certificate for app signing.

LAT serves as your reality check before going live. Use it when you need feedback from actual users interacting with your IAP implementation in the production environment. It helps you catch issues that only surface with real user behavior patterns. Users will interact with your app in ways you didn't anticipate during development, and LAT surfaces these scenarios early.

LAT validates the complete user experience—including payment processing, receipt delivery, and content unlocking. But here's the key: IAP purchases are free during LAT test sessions, so no one gets charged.
 

Setting up LAT

LAT setup involves the full app submission process plus tester management. Here are the primary steps from the LAT workflow:

1. Create your app listing in the Developer Console if you haven't already.

2. Navigate to Live App Testing and click Create a new Live App Test.

3. Upload your app build APK file and complete the required metadata fields.

4. Add IAP items, submitting with the "Submit to Test" (not "Submit to Test and Live") option. These test IAP items get a "TEST" label and are only available during LAT.

5. Add testers, either individually or via CSV upload.

6. Submit your test. Your testers will receive email invitations and push notifications when ready.

7. Monitor and collect feedback through the LAT dashboard as testers use your app.
 

What to test with LAT

Focus on real-world scenarios that only emerge with actual users:

• User experience flows: How users discover and purchase IAP items, and whether purchase confirmations make sense to first-time users.
• Real usage edge cases: Users switching devices mid-purchase, backgrounding apps during transactions, or poor network connectivity during checkout
• Performance under realistic conditions: Multiple concurrent users and varying device performance that stress-test your implementation

Since LAT uses production Amazon services with real user accounts, you get the most authentic testing environment possible while still maintaining control over who can access your app. When testing is complete, you can promote your test IAP items to live status for your actual release.

Each tool has its place. The most effective approach follows a simple progression:

App Tester ⇒ DevTest for IAP⇒ LAT
 

This catches issues early when they're cheap to fix while building confidence as you move toward production.

•  Start with App Tester during initial development to validate your basic implementation.
• Move to DevTest once your code is solid, but you need to test against real Amazon services.
•  Use LAT when you're confident in your technical implementation but need real-world validation before release.

Keep comprehensive logging throughout all three test flows. Each testing tool gives you different feedback. Sometimes, correlating logs will help you identify patterns that might not be obvious from any single testing approach.

Your users expect IAP functionality that just works. When you've got the right approach to testing, that's exactly what you'll deliver.

• IAP Testing Overview
• About Appstore DevTest for IAP
• App Tester User Guide
• Understanding Live App Testing