Hanmoto provides a simple way to manage public pages with Asset Pipeline.

HasAccounts is a full featured Rails gem providing models for financial accounting.

Easy access and creation of "has many" relationships for ActiveRecord models. It uses a "vertical table" so schema changes aren't necessary when you add fields. Use this plugin to add preferences, options, flags, etc to your models

Put EAV behaviour on your ActiveRecord models

An Active Model validator that uses the face.com API to ensures an image contains a face

Simple heartbeat monitoring target for Rails apps with database connection testing, customizable output, HTTP status code, and Airbrake notification.

Store ActiveRecord IDs non-obviously in URL using hashids.

Allow addition of custom 'magic' columns to ActiveRecord models.

Custom fields forActiveRecord models, suppport Rails 4!

Simple replacement for has_many_polymorphs

Moderated fields or whole model instances are serialized and saved into a separate moderations table. The moderation can then be accepted and the changes will be applied to the model. This way, lookups for existing, accepted fields or entries will be much faster than if using something like Papertrail, since the changes that have not yet been accepted are stored outside of the model table - in the moderations table.

Keep specified associations in sync with ease using async reindexing (searchkick gem is required).

vCard like contact and address models and helpers for Rails.

Headhunter is an HTML and CSS validation tool that injects itself into your Rails feature tests and automagically checks all your generated HTML and CSS for validity. In addition, it also looks out for unused (and therefore superfluous) CSS selectors.

Take rails constants' loading under control

Helena is an online survey/test framework designed for agile survey/test development, longitudinal studies and instant feedback.

Ruby library for image galleries generation.

heroku_external_db lets you specify multiple databases using Heroku-style DATABASE_URL parameters, wire them up to different ActiveRecord configurations, and automatically configure it from the Rails environment. It also adds support for the :sslca configuration parameter so you can talk to external MySQL servers over SSL.

Quickly and easily add SSL to a Rails App with Let's Encrypt

New Relic (on Heroku) currently reports queue times as queuing at the router level. The goal of this gem is to provide new relic with the proper queueing time for requests, which takes into account queue time at the dyno level.