For our main web app, we run the Linux operating system, Apache and Nginx web servers, the MySQL database, and PHP using the Laravel framework. It’s commonly referred to as a LAMP stack. All code is managed in GitHub.
In addition, we use a variety of other technologies for specific use cases including AngularJS, ReactJS, Elasticsearch, Redis, MongoDB, and Firebase.
Our iPad and iPhone app (it's one app) runs on iOS, of course. It is a native app coded in Swift.