React Native Expo Offline Network Detect and Data Sync Source Code

Fullstack source code bundle for backend API with express.js (json file persistence) and Frontend with react-native with expo.io. Frontend user interface detects when it has network access (to internet) and saves data structures in devices SQLLite Databases for syncing to backend when network is reached. These base code was used for a social census collection where celular data is unreachable and offline data syncing was a must. Also was used in mobile family health units to keep e-health records in poor communities. 

A live demo is available at exp://exp.host/@obetancourth/offlinedemo must use expo client to view in android or iPhone (https://expo.io/tools#client). Live demo backend runs on heroku free gears data will be reseted time to time. 

After purchase you must install dependencies by running npm install on both backend and frontend dependencies. Start backend with npm start, start Front-end with npm-start (iOS, Android emulator or Expo Client on phone needed)