Questions
The CSV file needs to have two header columns: sku and qty. The header names have to be in lowercase.
You can download a sample file from this link.
You can use CSS to target the elements of the application and style it as you wish.
Yes, you can install the app on any page of the store provided that you can add the code that we generate to it. For example, you can add it to a custom category page, or even a custom product page. You are not limited to a specific URL or page type.
To add text or other elements to the page you simply modify the content of the page where the app is installed making sure to leave the generated code intact.
For example, to add sme instructions above the application you simple add the text above the AppMain container as shown in this screen shot:
It is posible to change using a manual intervention.
We are working on making this easier to edit, until then please use the support form available from the app to request this change.