I've published apps in the Apple and Android app stores. I've principally used React Native, and in most cases the apps I've built have been to demonstrate a proof of concept, such as porting a high performance in-memory database into iOS or interfacing with a bespoke home router or integrating open source VPN (Wireguard) code into a React Native app.
This app was published on Google Play and the App store. Written in React Native, it connected to a Nodejs backend and provided a clean, simple interface of buttons for managing a variety of tasks
Defence against Dark Artefacts
I built a prototype app that supported the management of a users home network. It allowed users to sketch the devices in their home and used Google's Autodraw API to provide icons. I generated React Native bindings to the open source Wireguard code and created VPN connections by tapping RFID tokens against a smartphone.
I built an iPhone / iPad app in Objective-C which integrated a bespoke high performance in-memory circular database (written at Glasgow University) that was used to monitor and control devices on the network. The app presented a comic-book style interface for creating network policies (i.e. time constrained access to the Internet).