Everything you have hearted, with today's price. This list lives in this browser only — no account needed, and we cannot see it.
Price alerts already work without an account — heart a gym, add your email. An account would sync the list across devices and let you rate the gym you actually go to. Tell us if that is worth building.
Anonymous, and it takes ten seconds. We publish the aggregate on each gym's page once enough people have rated it, and show gym owners what their own members say — which is the only feedback most of them ever get that is not a complaint.