My Android flutter app is already live on Google Play and runs on a monthly subscription model through Play Billing. I now need to introduce a clear ad-supported tier without disturbing the experience of paying users. Here’s the flow I want: • If the user has an active subscription, the entire app stays completely ad-free. • If no active subscription is detected, a Google AdMob rewarded or interstitial video ad should play every five minutes while the app is in use. No other ad formats are required. You may reuse my existing Play Billing implementation to check entitlement, or refactor it if that makes the logic cleaner. What matters is that the subscription check is fast, reliable, and cannot be bypassed. Deliverables 1. Updated Android project with AdMob video ads integrated and conditioned on subscription status. 2. A brief hand-off document (or inline code comments) that explains where I can adjust the five-minute timer or switch ad types in the future. 3. A signed release-ready APK or AAB so I can test on my own device before uploading to the Play Console. Acceptance criteria • Paying subscribers never see any advertising, even after reinstalls or device changes. • Non-subscribers reliably receive an AdMob video ad within five minutes of first launching the app and at subsequent five-minute intervals. • No crashes, ANR, or policy violations flagged by the Play Console when uploading the build. The codebase is in Kotlin with a few Java classes, and we target API 24+. Feel free to use the latest AdMob and Play Billing libraries as long as they stay within Google policy. Let me know if you need version control access or a test account; I can provide both right away.