Peastash allows you to instrument your code with the ELK stack easily.

Sparklines are small but intense charts.

Use Percona (pt-online-schema-change) for migrations generated with this tool, all activerecord helpers are available.

Perfm aims to be a performance monitoring tool for Ruby on Rails applications.

Periodic Calculations gem allows you to retrieve periodic results of aggregates that can be accumulated over time with PostgreSQL.

Enforces DDL/migration safety in Ruby on Rails project with an emphasis on explicitly choosing trade-offs and avoiding unnecessary magic.

Rails assets admin panel theme pack to standardize theming across PHCDevworks plugins & applications.

A bunch of helpers and goodies intended to make life with Phlex even easier!

A mountable Phrasing adapter for editing images inline.

Use picturefill with Rails :)

Rails View Helper picture_tag extension

A gem for Ruby on Rails that will track key metrics (memory, request time & SQL Requests) for request & feature tests.

The piwik_analytics gem provides an easy way to include Piwik into your application. By default it will output the synchronous piwik tracking code for every page (given that it is configured correctly).

This gem provides all necessary tools to make a Rails application into a platform with third party applications.

Special kit that allows you create html5-ready Rails 3 apps quick with pre-included few useful libs in your app

Page-specific javascript for Rails applications with the ability of passing data.

Drop in feedback engine with customizable fields, and captcha available

Uniform Omni-Relational ActiveRecord Tools. Includes polymorphic and any belongs_to relation.

Polymorphic content blocks made simple.

Simplified polymorphic full text + similarity search based on postgres