Mobile app with geo functionality

I need a mobile app for Android maybe later for iPhone. It tracks proximity of airspaces used by drones for the user of the app. Here's how it works: - Download a data file containing valid drone airspaces from our server. The format is to be discussed but most probably a sqlite db file with data on airspaces as well as their polygon geometries. - Caches it locally (on startup looks for a new version, at least every 6 (configurable) hour it looks for a new version). Apart from this download there is no other network traffic. - Based on users geolocation the app queries the local datastore for the closest airspaces. Once an airspace is closer than a configurable distance in meters lets say 200 meters it alerts the user using a push notification and playing some sound. - On the app screen basically not much is happening. It displays some branding, a logo, a link to our mapping system ([login to view URL]). - Also on the screen, if an airspace is getting close to the user the basic data of it is also displayed along with its distance updated every (configurable) 1 sec, and a link taking the user to our website in the system browser, with more details. There also needs to be switch to turn notifications off-on. - The app needs to run in the background as well also providing the notifications while in background. Other issues: - The app would be built preferably in React Native (open to other suggestions). - I need all source codes committed to a gitlab project. All issues will be dealt with there. - I need documented source code as well as reproducable build intructions. - The data download server api is not your concern, once we agreed upon the communication parameters we will make it happen. - Payment upon completion in one batch. - Further tweaking and new features of this app can be expected upon successful delivery. Proposal should contain experience and plans for carrying out this and also a timeline. If you have any question please ask!