StoreKit 2 and Google Play Billing feeding a single source of truth.
Native purchase flows with StoreKit 2 and Google Play Billing, server-side JWS verification, and one entitlement synced across iOS, Android, tvOS, and web. Day rate: €500 or $600.
StoreKit 2 and Google Play Billing model products, receipts, and server notifications differently. Apple gives you signed transactions and JWS, Google gives you purchase tokens and Real-time Developer Notifications, and the product setup in each console follows its own rules. Sylvain builds the native purchase flow on each side so it follows the platform's intended pattern, then maps both into a single internal model your backend understands.
A user who subscribes on iPhone expects to be subscribed on their Android tablet, their Apple TV, and the website. That only works if entitlement lives on your server, not inside one app. Sylvain wires both stores to a single source of truth so access is consistent everywhere, and so the app asks your backend what the user can access rather than guessing from a local receipt.
Trusting the client alone invites fraud and breaks on refunds. Sylvain implements server-side verification of Apple's JWS transactions and Google's purchase tokens, and handles the server notifications that report renewals, cancellations, billing retries, and refunds. This keeps entitlement accurate even when the change happens outside the app, for example when a user cancels from the store settings.
Free trials, introductory offers, and restore purchases each have platform-specific behavior that confuses users when done wrong. The store fee is also real: roughly 15 to 30 percent depending on program and tenure. Sylvain implements these flows directly, and if you prefer, integrates RevenueCat to centralize receipts and reporting. He will give you an honest view of when RevenueCat saves time and when going direct is simpler.
The flat day rate is €500 or $600, remote, with no agency markup. Note this is the development cost; the store fee of roughly 15 to 30 percent is separate and paid to Apple or Google.
Yes. I often pick up an app with a half-working purchase flow and fix verification, restores, or entitlement sync. I review the current StoreKit or Billing code before proposing changes.
Either. I can wire StoreKit 2 and Google Play Billing directly to your backend, or integrate RevenueCat if you want centralized receipts and analytics. I will tell you which fits your case.
Entitlement lives on your server as a single source of truth. Both stores report to it through verified transactions and server notifications, so iOS, Android, tvOS, and web all see the same access.
Yes. I verify Apple's JWS transactions and Google's purchase tokens on the server and process the renewal, cancellation, and refund notifications, so entitlement stays correct even for changes made outside the app.
Yes. I implement free trials, introductory offers, and restore purchases following each platform's rules, and test them on real accounts so users do not get stuck or double-charged.
Send the product context, target platform, repository state, and timing. I will tell you quickly if I can help.