If you want to use Focuster with your iOS device, you should look here:
Help us beta test the next version of Focuster for iOS:
We are currently running an iOS public beta. You should join if you want to help us test new features and report bugs.
Open this link on your iOS device to join the beta and download the app:
https://testflight.apple.com/join/kLNfG2HQ
Please follow the directions and reach out for support if you have any issues or suggestions!