Back in Use review for APO Product Options, Variants

This is probably the dumbest app in the entire Shopify app store. Everything works perfectly, so you'd say it's a brilliant app. However, that's not the case, the stock of the products for which you use this app is no longer kept track of, and the support simply tells me that I should then do this manually. I use this app to offer an extension of the warranty on my products. From 1 to 2 years, so now I have to manually keep track of the stock of my entire shop. This is like going back to the Stone Age.