Reqmunk: Require add‑ons

Reqmunk is exactly what we were asking for to require an add-on at checkout. In our case, we needed a way to attach a required shoe accessory (which is required for the curling shoe to function properly) to a shoe purchase while keeping both sides SKUs intact. It's not a bundle and it's not an upsell. It's a *requirement*. This app saves us dozens of uncomfortable "sorry, but your order is actually more expensive" follow up emails to customers who missed instructions in a generic bundle app.