I launched a competitor to a public laundry machine service. It works on CSCServiceworks machines (around 100,000 locations across the US).
I open sourced the code used to build the service after I was ordered to take the app down: https://github.com/Shakira4242/cscpay_app.git
This was my first iOS app published on the app store. I learnt a lot about apple design guidelines and the app submission process. While I was comfortable using React Native for 80% of the project, some parts required obj-c and swift modules for certain functionality. In all, I got up to speed with deploying updates and feel much more confident repeating the process in the future.