It is possible to customize or translate the names of some fields in the app. This can be done in the CMS if you navigate to Administration > Translations.
In the field showing you can type in the name of the field or part of the name which you want to edit, it is important that you are searching for the English name so make sure you change your app language to English before to make sure you are typing in the correct field name.
You can as an example search for “In stock” and then select the result showing. You will then see on the right hand side the languages which you can choose your own translation for or change in this case the English name to Item in stock instead.
Once you have changed the name of the field you wanted to you can then scroll down and press Save.