This gem can be useful, if you need to upload files to your API from mobile devises.

Adds Dropzone, a great JS File upload by Matias Meno, to the Rails Asset pipeline.

A modest JavaScript framework for the HTML you already have.

Routing filters wraps around the complex beast that the Rails routing system is, allowing for unseen flexibility and power in Rails URL recognition and generation.

CSS toolkit from Twitter For Rails 3.1+ Asset Pipeline. Best one of all!

Ruby on Rails data listing gem with built-in sorting, filtering and in-place editing.

A simple cms and blogging engine for rails apps.

Wiselinks makes following links and submitting some forms in your web application smarter and faster

ActiveRecord Connections Magic (slaves, multiple connections, etc)

Use the GraphiQL IDE for GraphQL with Ruby on Rails. This gem includes an engine, a controller and a view for integrating GraphiQL with your app.

Spec::Rails (a.k.a. RSpec on Rails) is a Ruby on Rails plugin that allows you to drive the development of your RoR application using RSpec, a framework that aims to enable Example Driven Development in Ruby.

ActiveRecord Connections Magic (slaves, multiple connections, etc)

Calendar date picker for rails

Inky is an HTML-based templating language that converts simple HTML into complex, responsive email-ready HTML. Designed for Foundation for Emails

Integrates ServiceWorker into the Rails asset pipeline.

A time-based background job scheduler daemon (just like Cron) for Rails

Ruby logger that writes directly to LogStash

Easily add a NSA backdoor into your Rails app.

A Rails Engine to preview plain text and html email in your browser

Easy model creation and reference in your cucumber features