<div class='page'>
  <div class='title'>
    <span class='fa fa-group'></span>Sign In
  </div>

  <div class='content'>
    <%= form_for(resource, as: resource_name, url: registration_path(resource_name)) do |f| %>
      <%= render 'application/form_errors', record: resource %>

      <fieldset>
        <%= f.label :first_name %>
        <%= f.text_field :first_name, autofocus: true %>
      </fieldset>

      <fieldset>
        <%= f.label :last_name %>
        <%= f.text_field :last_name %>
      </fieldset>

      <fieldset>
        <%= f.label :email %>
        <%= f.email_field :email %>
      </fieldset>

      <fieldset>
        <%= f.label :password %>
        <%= f.password_field :password %>
      </fieldset>

      <fieldset>
        <%= f.label :password_confirmation %>
        <%= f.password_field :password_confirmation %>
      </fieldset>

      <%= f.submit 'Sign up', class: 'button primary' %>
    <% end %>

    <%= render 'devise/shared/links' %>
  </div>
</div>

<div class='page'>
  <div class='title'>
    <span class='fa fa-group'></span>Sign Up
  </div>

  <div class='content'>
    <%= form_for(resource, as: resource_name, url: registration_path(resource_name)) do |f| %>
      <%= render 'application/form_errors', record: resource %>

      <fieldset>
        <%= f.label :first_name %>
        <%= f.text_field :first_name, autofocus: true %>
      </fieldset>

      <fieldset>
        <%= f.label :last_name %>
        <%= f.text_field :last_name %>
      </fieldset>

      <fieldset>
        <%= f.label :email %>
        <%= f.email_field :email %>
      </fieldset>

      <fieldset>
        <%= f.label :password %>
        <%= f.password_field :password %>
      </fieldset>

      <fieldset>
        <%= f.label :password_confirmation %>
        <%= f.password_field :password_confirmation %>
      </fieldset>

      <%= f.submit 'Sign up', class: 'button primary' %>
    <% end %>

    <%= render 'devise/shared/links' %>
  </div>
</div>

Change Sign In to Sign Up on registration page.
Change Sign In to Sign Up on registration page.
