This is an adapter gem which allows you to use Judge from within your SimpleForm forms.
Do this in your Gemfile:
gem 'judge-simple_form'
Remember to setup Judge in your SimpleForm initializer:
config.wrappers do |b|
b.use :judge
end
Then add :validate => true
to the input options in your views. That's all.
<%= simple_form_for(@user) do |f| %>
<%= f.input :name, :validate => true %>
<% end %>
Judge is a client-side validation gem for Rails.