We have experience in all aspects of what you need to build:

• An app where users can make payments/manage subscriptions
• A backend that manages users, verifies payments, sends notifications, etc.
• And we can build a website too if needed. It can be as simple as a WordPress site/landing page or it can be the full app experience online. 

Last year we built the Kandiid.com app in React native which peaked at #71 in the app store for photo & video. It's a social networking app where users can upload, buy and sell content. We also have some initial support fo live streaming and NFT/blockchain integration which we're building out over the next few months before releasing them.