Inventory Planner by Sage

So far we have been very happy with Inventory Planner (IP). The functionality is great, and it has a lot of features that we are really looking forward to using. However the best thing about Inventory Planner is the incredible responsiveness of their customer support. Jill, Nick and the rest are spectacular! They routinely go above and beyond what one would expect from customer support. They are very to tweak things till you get what you need. There is one minor downside if you have tens of thousands of products: product sync between Shopify and IP is slow. We have 50K products, and it takes about eight hours for a new product in Shopify to appear in IP. EDIT: And they fixed that problem!