What are the best PostgreSQL as a Service Tools?

Amazon RDS for PostgreSQL, Heroku Postgres, Google Cloud SQL for PostgreSQL, Azure Database for PostgreSQL, and ElephantSQL are the most popular tools in the category "PostgreSQL as a Service". "Easy setup, backup, monitoring" is the primary reason developers pick Amazon RDS for PostgreSQL over its competitors, while "Easy to setup" is the reason why Heroku Postgres was chosen.