Build a custom form for your base on one device and it stays there. Airtable gives you no built-in way to carry that setup across to your other devices, so getting the same form onto your phone or tablet means rebuilding it by hand or exporting it yourself.
Air Fill is working on a fix for exactly this: start a form on one device and pick it up on another, with your setup already waiting for you. It’s in development now, and it’s designed so the work you do once is the work you keep, wherever you happen to be building.