Once you create a charge, a customer has to approve it, at which point they'll be redirected back to your app with a charge_id parameter. From there, you can activate the approved charge to commence the billing cycle.
Once you activate the charge, the recurring application charge 'status' becomes 'active'. If you see the charge is active, you can keep a record on your side to know they're paying.
If a customer uninstalls you app, the charges are automatically stopped.
If you're even unsure if a customer is paying, get their recurring application charges and look for an active charge.
We no longer need to "activate" the charge.
Once the merchant approves the subscription, the subscription status will automatically change from "pending" to "active" (no more "accepted" in between).
We will get the charge_id query parameter with the return url. Use this to check if the subscription is indeed active with,