Joe Guilmette from WP All Import created a service that offers, “free, unlimited WordPress installs,” for anyone who needs a temporary site. The name of the service is (ridiculously) poopy.life, a clever effort to prevent people from always using the free plan.
Had I been advising Joe, I would’ve told him to use the wpsandbox.io domain (which is what they’ll use for a commercial version of this service) for the free service as well, but put the actual sandboxes on the poopy domain. Anyway, it’s a fun little service, and the ability to save an install as a template is handy.