With some limitations, yes! Your staging URL (i.e. mysite.webflow.com or in Duda) can always be used as a test environment, and our reviews app is FREE on your test URL until you publish it to your own domain.
You can similarly test abandoned cart recovery, affiliates, multi-currency, and more.
Our subscriptions app has a big caveat. Webflow itself doesn’t support Stripe Test Mode, unfortunately (so nothing we can do to help there). As a result, all Stripe transactions must be real. You can, however, simply process orders yourself then refund yourself. This is the easiest way to test transactions on Simple Subscriptions.