Both Android and iOS versions can be downloaded from https://www.kashkarnival.com.au/.
iOS users can download directly from the Apple App Store: https://apps.apple.com/app/id1021856470
Installation instructions on how to install the APK on Android devices can be found here: https://www.kashkarnival.com.au/download/#install-instructions
Please ensure your met minimum specification requirements. This information is available on the download page of the Kash Karnival website.