Technical specification:

On the front-end we used Visual Studio together with the Xamarin framework, allowing us to build a cross-platform mobile app that works both on Android and iOS, the programming language we used is C#. To allow persistent local data storage we used the lightweight Realm framework.
On the back-end we set up a Virtual Private Server, which has a public IP address and a dedicated port to handle data sent from the front-end of the app to the back-end via a socket library. The server runs a Node.js backend combined with a MariaDB database to handle server side data storage.