There's no app yet, but there is a Progressive Web App (PWA) which is like a website in its own app. If you use Chrome, you can get the PWA by going to kbin's front page, open Chrome's three dot menu, then press "Add to Home screen."
Are you using a VPN like Adguard? I also had that problem and disabling it temporarily allowed me to install the PWA properly instead of a home screen short cut.