ActionController is great, but could be better. Here are some tweaks for it.

The Mosaico email editor on Rails.

Simple and lightweight paginator for collections (Array, ActiveRecord::Relation etc.)

action_processor

Send push notifications to browsers

ActionScope provides a comprehensive set of dynamic scopes for ActiveRecord models, including basic column filtering, text matching, range queries, association scopes, multi-column search, and sorting capabilities. Automatically generates scopes based on model attributes and associations.

Group access authorization control, based on controllers actions access permissions using ActionSentinel.

Action Throttler is an easy to use Rails plugin to quickly throttle application actions based on configurable duration and limit.

Helper for generate input tags automatically by detect column info

Validate your ActiveAdmin resources through dry-validation

Allow user to export/import of ActiveRecord records and associated records in ActiveAdmin.

Drag and drop order interface for ActiveAdmin tables

An out of box API built for Rails.

Provide export / import to ActiveRecord

Audit support for Active Record

Implementing pathfinding for Rails records

Make ActiveRecord models bookable with availability rules, schedule etc.

ActiveRecord integration with the MusicBrainz database

Suggests validations and associations for ActiveRecord models

This gem provides a macro for comparing the column and the other column of the record. Type of the comparable column is Date Time Numeric, and all that jazz.