RubyGems were developed to simplify and accelerate the stages of the application creation deployment and library connection. Utilizing this package manager for Ruby saves you time as you get ready-made solutions to almost any task instead of writing the functions from scratch. Each gem contains a particular element of functionality including all related files. Unfortunately they aren structured in any way so in order to find ruby gems it better to use a regular search engine and the required key words (check GitHub s ). Our dedicated development team also actively employs Ruby Gems in the process of software development. Here is the top of the most popular and useful ruby gems according to our experience GeoCoder s . Being able to connect through itself over 4 APIs this Ruby gem implements both the direct and reverse geocoding by IP address geographical coordinates and even real physical addresses (e.g. the address of the street). Bullet s . The most downloaded Ruby gems out there. It was initially created with an intention to boost software performance. It does so by decreasing the total amount of client-server requests. Basically Bullet tracks the N+1 cases of requests and notifies the developer when other tools can be used instead (e.g. cache counter). Pry s . We rmend to simplify the bug fixing procedures for your RoR-based application with the Pry gem which is a more advanced alternative to the standard IRB wrapper. ActiveModelSerializers s (which starts lagging while processingpound documents) and uses caching. Fast JSON API s . Fast JSON API wille in handy when you need fast serialization of software code. It works much faster than Wicked PDF s . This gem is working alongside with wkhtmltoPDF s and helps realizing an interaction with the DSL generator. Devise Masquerade s . This Ruby gem helps developing multi user apps. In particular youll be able to test your app from the perspective of users with different levels of access. Devise s . Based on the MVC model the Devise gem can provide secure user authentication and session management. Letter opener s . If you need to create a newsletter mechanism to send notifications to all users that launched your app this gem will help you do that much easier you won need to integrate and configure your own SMTP server. Money Rails s . If you are planning to integrate your app with Ruby Money this gem wille in quite handy. Pundit s . A tool that allows defining different levels of access to the app functionality according to the rights of an authorized user.