drapergem/draper: Decorators/View-Models for Rails Applications
Draper adds an object-oriented layer of presentation logic to your Rails application. […] Without Draper, this functionality might have been tangled up in procedural helpers or adding bulk to your models. With Draper decorators, you can wrap your models with presentation-related logic to organise - and test - this layer of your app much more effectively.
Source: drapergem/draper: Decorators/View-Models for Rails Applications
Haven’t used this, but it’s often brought up by Rails developers.