APO Product Options, Variants

The app does exactly as described, and does it well. The conditional logic is excellent and gives plenty of flexibility to enable me to control the various allowed permutations of my options. Their support is top class. I had a minor niggle when I moved to one of the Shopify 2.0 themes so e-mailed MageWorx and got a response mere minutes later, and resolution by the following day. They couldn't have been any better!