Also stay in the loop with what's going on through these awesome links:
Currently we have the following 5 variant options that are predetermined for all merchants: Style, color, size, type, and material. However, those don't allow merchants to get creative with the types of products and how they enter them on the app.
We should allow them to create their options just as we do for the custom fields where they can specify the name and save it. This will need to work between MXM web and MMR, so the settings will live on MXM web under product settings and then when creating a new product they will be able to select from the 5 standard as well as the new ones that were created by the merchant.
Default:
They can override and change those as well as add their own to that list by clicking the green (Add Variant Option)