List of Useful Heroku Add-ons
With over 3 years experience building Ruby on Rails applications over Heroku platform, I found there are many useful Heroku Add-ons to make your development process easier, faster, more effective, and even : simpler. Please keep in mind that all add-ons listed here is useful for general case and not all of them are useful for a specific case. Therefore, if you just started with Heroku, you will see all of those items in the following list are very useful. Let's started with the list...
There are two free and useful add-ons in database category: Heroku Postgres and PG Backups. Heroku Postgres provides you with free started database for you application (more advanced paid plan is available, of course). PG Backups provides you with ability to back-up your Heroku Postgres database safely.
To boost your Rails application performance, caching is a must. Heroku has provided you with Memcachier for utilizing memcache on your Rails application. Prefer to use Redis over Memcache ? Here you go : Redis To Go add-ons. There's also Memcached Cloud add-ons which only available for US regions (currently)
Logging, Monitoring, and Scheduling
For logging, Logentries does a great job for alerting you with any unusual event on your application's log. Beside logging, it also very helpful for sending you an alert directly on your e-mail if, foreexample, your application hits timeout.
For monitoring the performance, New Relic is my favourite. It provides you with details of your application performance such memory usage, database performance, front-end performance, etc. This will help you to tweak your application performance to reach the next level.
For scheduling, Heroku Scheduler provides you with very easy set up. It allows you to set up a repeated event each 10 minutes, each hour, or each day. If you need more advanced scheduling for repeating event every 1 minute -- for example -- you can set up a gem named Clockwork which is officially supported by Heroku.