In order to sync your recipes between the iPhone and the iPad, please install the app on both of your devices. Then you need to sign up for an account.
So let’s say you start with the iPad, where most of your recipes are.
(If you already did that: just make sure you are still logged in).
(The rounded arrow icon on the top left corner of the main screen).
If you are already logged in on your iPhone: tap the “sync” button there as well.
All the previously uploaded recipes from the iPad will be copied from your cloud account and brought to the app on your iPhone as well.