Also I am not sure how to transfer the presets from a computer to the H9 app?

I'm assuming you mean from a computer to the iOS version of H9 Control.  Well, you can export inidividual presets or preset lists in the Preset and Preset List screens, and you can export all of your presets and/or preset lists in the Export screen under Settings.  You can email yourself the resulting file, open the email on an iOS device, and right click on the file to open it in H9 Control.