As a Plaform as a Service provider (PAAS), Heroku simplifies the process of running web application. One of its most powerful features, the Heroku Elements Marketplace, allows 3rd party developers the ability to write plug and play features to make hosting even easier. The best addons grant new functionality, provide greater flexibility, or save money for application owners.
Papertrail
Heroku's CLI logging is useful for monitoring your application live but its not possible to check for logs far into the past. Papertrail is a cloud-hosted log management solution making it easy to search through your logs. Logs are compiled across dynos and centralized in an seamless to use search console. In addition, it supports intelligent alerting for all Heroku applications. Overall, a very useful addon for any Heroku application.
Autoidle
Autoidle is best for Heroku Applications that leverage the pipeline and make generous usage of review and staging applications. It automatically puts your staging and review apps to sleep when you don't need them. Meaning you only pay for dynos you are actively using.
New Relic
New Relic monitors critical transactions across your application environment with end-to-end transaction tracing. Identify bottlenecks with a low-impact thread profiling tool that periodically captures the stack trace of each thread for a specified duration. Drill into front-end and back-end applications to identify the root cause of performance issues. Supports front-end JavaScript and back-end Ruby, Java, Python, Node.js, and PHP.
Rollbar
Rollbar is a continuous code improvement platform. It reduces noise in error monitoring by removing duplicates from error list. Meaning there is less manual effort to triage issues and more time fixing bugs. Get real-time alerts on errors as new code is shipped in an easy to read dashboard. Integrations with GitHub or Bitbucket make it easy to identify problematic Pull Requests.
Dynoscale
Dynoscale is absolutely mission critical for applications hosted on Heroku. As traffic to your site grows, more dynos are needed to manage the demands of your users. Its impossible to manually monitor traffic at all times so this Heroku Addon scales your application based on real user load. By cutting down on your Dyno usage, you save money yet are able to provide a great experience no matter the traffic to your site.
heroku addons:create dscale