Stitch offer three tiers: Basic. Standard and Power. When you sign up for Stitch, you're automatically set up with the Basic tier, a free plan. Standard and Premium contain additional features that you can access by purchasing a subscription. If you're an admin, you can purchase a subscription from the Billing section.
For more information on how this works, see our article on subscribing.
For information on how much each tier costs, see our pricing page.