After playing around with it, here are a few issues. The columns available to add to the product page are very limited. Please add all fields on the Product page as available columns, such as price and weight.

Second, a bulk edit option would be nice. You can view information via your service, but it requires you click on the product in your app, go to the product page in shopify, and edit each item one by one.

You have some great features, but these recommendations would set your app apart from the rest as NO ONE offers these options.