In this article I look at creating a cross platform mobile tracking app with react-native / expo, AWS Amplify, and Amazon Location Service
https://aws.amazon.com/blogs/mobile/cross-platform-mobile-tracking-app-with-aws-amplify-and-amazon-location-service/
https://aws.amazon.com/blogs/mobile/cross-platform-mobile-tracking-app-with-aws-amplify-and-amazon-location-service/