Absolutely terrific news from Heroku.
We are happy to announce the general availability of Automated Certificate Management (ACM) for all paid Heroku dynos. With ACM, the cumbersome and costly process of provisioning and managing SSL certificates is replaced with a simple experience that is free for all paid Dynos on Heroku’s Common Runtime. Creating secure web applications has never been more important, and with ACM and the Let’s Encrypt project, never easier.
SSL wasn't hard on Heroku before, but it was expensive: $20/mo for enabling SSL and then another $20/mo for an SSL certificate. Recently, Heroku introduced Heroku Free SSL, built on Server Name Indication (SNI), resulting in savings they passed on to their customers. Now, using Let's Encrypt, they can pass on further savings - the SSL certificate. Bottom line: SSL that used to cost $40/mo is free.