I am an expert in creating cross-platform mobile apps using React Native and native iOS using Swift. While I have a strong knowledge of basics, such as common design patterns (MVC, MVVM), programming languages (Swift, JavaScript) and standard mobile frameworks (In-App Purchases, Maps, Camera, Push Notifications, etc.), I also have a great experience in a wide number of third-party SDKs: Facebook, PayPal, Stripe, Google Maps, ad networks, etc. My backend experience is in Google Firebase. Using Google Cloud Firestore as a database and Firebase Cloud Functions written on TypeScript I can easily create a robust backend for mobile and web apps. In 2019 I started to move to cross-platform development using React Native. The work I provide is of the highest quality, fully responsive, and tested in a wide range of devices. I take great care to ensure each project is well-architected, well-documented, and easily maintainable so you can enhance an app as your company grows. I'm also familiar with implementing in-app payments, like In-App Purchases and subscriptions, Apple Pay, PayPal and Stripe SDKs (both client-side and server-side). My wide experience with location-based applications allows me to help with choosing the optimal ways for the performance of the application, which leads to an increase in a company's revenue ??. I can guide through the Apple app review process to make it smooth and avoid any rejections.