You can setup a Paprika account to keep your recipes, grocery lists, meal plans, and other data synced between your devices. To create a Paprika account, go to Settings -> Cloud Sync and press Sign Up. Once you have an account, make sure you are logged into the same account on all of your devices.
Please note that Paprika is sold separately for iOS, Mac, Android, and Windows. So depending on the devices you are trying to sync you may need to purchase the version of Paprika for those devices. For example if you have an iPhone and a MacBook you would need to purchase the iOS and Mac versions of Paprika. If you have an Android phone and a Windows PC you would need to purchase the Android and Windows versions of Paprika.