Link doesn't work for me. From another source I found:
Free – Experiment in your own dev or demo app with a web and a worker dyno for free. Sleeps after 1 hr of inactivity. Active up to 12 hours a day. No custom domains. 512 MB RAM.
Hobby – Run a small app 24×7 with the Heroku developer experience for $7/dyno/mo. Custom domains. Run a maximum of one dyno per Procfile entry. 512 MB RAM.
Standard 1X, 2X: Build production apps of any size or complexity. Run multiple dynos per Procfile entry to scale out. App metrics, faster builds and preboot. All Hobby features. 512MB or 1GB RAM. $25 or $50/dyno/mo.
Performance – Isolated dynos for your large-scale, high-performance apps. All Standard features. Compose your app with performance and standard dynos. 6GB RAM. $500/dyno/mo.
Free – Experiment in your own dev or demo app with a web and a worker dyno for free. Sleeps after 1 hr of inactivity. Active up to 12 hours a day. No custom domains. 512 MB RAM.
Hobby – Run a small app 24×7 with the Heroku developer experience for $7/dyno/mo. Custom domains. Run a maximum of one dyno per Procfile entry. 512 MB RAM.
Standard 1X, 2X: Build production apps of any size or complexity. Run multiple dynos per Procfile entry to scale out. App metrics, faster builds and preboot. All Hobby features. 512MB or 1GB RAM. $25 or $50/dyno/mo.
Performance – Isolated dynos for your large-scale, high-performance apps. All Standard features. Compose your app with performance and standard dynos. 6GB RAM. $500/dyno/mo.
H/T http://notes.ericjiang.com/posts/881