In order for you to download our application on your iOS (iPhone) device you need to access the AppStore application on your device, look up Stoiximan application and download it directly from there.
You may also check this link that, although will not offer you the package installer, it gives you an overview on the application itself: https://apps.apple.com/gr/app/stoiximan-live-stoichema-se/id1081294809?l=el