We specialize in app creation with mobile payments. 

We can help you with: 

• RevenueCat set up 
• Apple App Store Connect set up 
• Google Play Console set up 
• Fixing issues
• Maximizing in-app purchase revenue 
• Connecting marketing and analytics integrations with mobile app  

We've done complex and uncommon development work about Apple and Google in-app purchases:  

• Migrating old payment systems to new ones 
• Subscription price rise with thousands of active subscriptions 
• Changing app owner, when an app is sold 
• Running subscription promotions 
• Compatibility of subscriptions between iOS, Android and Web apps 

I can consult you about whether to use Apple and Google payment systems or a Web-based system like Stripe, PayPal or similar. 

And how to avoid Apple & Google app review rejections when your app is about to launch.