...It uses MMKV by Tencent under the hood on Android and iOS both that is used by their WeChat app(more than 1 Billion users). Unlike other storage solutions for React Native, this library lets you store any kind of data type, in any number of database instances, with or without encryption in a very fast and efficient way. Read about it on this blog post I wrote on dev.to. Starting from v0.5.0 the library has been rewritten in C++ on Android and iOS both. It employs React Native JSI making it the fastest storage option for React Native. MMKV uses mmap to keep memory synced with file, and protobuf to encode/decode values to achieve the best performance.