The app is a Progressive Web App (PWA). This means it combines the best of both worlds: app and web.
You can use the app on any modern browser on any device.
It has been optimised for and extensively tested on Desktop, Laptop, Tablet and Smartphone (iOS and Android)
The app is not available on the App store because Apple places too many restrictions on how an app may be used. Basically we have to play their game and we are subject to their rules. This is very restrictive. You also would not be able to use it in the way that I intended across all devices.