Recharge
Recharge is the dominant subscription app for Shopify. It powers the "Subscribe & Save" widgets on PDPs, manages the recurring billing cycle, sends subscriber emails, and provides the customer portal where subscribers can skip, pause, swap, or cancel.
Why subscription matters: a store with 20% of revenue coming from Recharge-powered subscriptions has dramatically more predictable cash flow, higher LTV, and a higher exit multiple than a pure one-off store. Subscription-eligible categories (supplements, personal care, pet food, consumables) leave money on the table every day they don't offer it.
Main alternatives: Shopify's native Subscriptions app (cheaper, simpler, less powerful), Ordergroove (enterprise-grade), and Seal Subscriptions (budget).