All of Google's cloud offerings are available independently. You can use Cloud SQL, Cloud Storage, Datastore, Compute Engine, App Engine, BigQuery, DNS, and al

All of Google's cloud offerings are available independently. You can use Cloud SQL, Cloud Storage, Datastore, Compute Engine, App Engine, BigQuery, DNS, and all the APIs á la cart, and I'm sure the same will be true of Firebase. In case you don't know, the APIs that used to be bundled with App Engine back when it was the only cloud product, like Datastore, have been unbundled over time. I assume remaining App Engine-only APIs like cron are under consideration for unbundling, but there's no precedence for an already unbundled API being bundled to App Engine.