Padrino authentication between apps, to use e.g.: logged_in?

Question

I was following the Blog Tutorial of Padrino and now I'm faced with the problem that I have two apps: Admin, App and I don't know how to access the authenticated account coming from Admin inside App. For example, inside views/posts/show.haml I want to be able to use the logged_in? helper, but it's always returning false as I suspect the access to the current_account variable has to be done in some other way. What am I missing?

# admin/app.rb
 module MyCompany
  class Admin < Padrino::Application
    use ActiveRecord::ConnectionAdapters::ConnectionManagement

    register Padrino::Mailer
    register Padrino::Helpers
    register Padrino::Admin::AccessControl

    set :admin_model, 'Account'
    set :login_page,  '/sessions/new'

    enable  :sessions
    disable :store_location

    access_control.roles_for :any do |role|
      role.protect '/'
      role.allow   '/sessions'
    end

    access_control.roles_for :admin do |role|
      role.project_module :posts, '/posts'
      role.project_module :accounts, '/accounts'
    end

    # Custom error management
    error(403) { @title = "Error 403"; render('errors/403', :layout => :error) }
    error(404) { @title = "Error 404"; render('errors/404', :layout => :error) }
    error(500) { @title = "Error 500"; render('errors/500', :layout => :error) }
  end
end

# app/app.rb
module MyCompany
  class App < Padrino::Application
    use ActiveRecord::ConnectionAdapters::ConnectionManagement

    register SassInitializer
    register CompassInitializer
    register Padrino::Mailer
    register Padrino::Helpers
    register Padrino::Assets
    register Padrino::CSRF

    configure :production do
      set :js_compressor, Uglifier.new(mangle: false)
      set :css_compressor, :yui
      set :precompile_assets, [/^\w\.(?!(?:css|js)$)/i]
    end
    configure :test do
      set :raise_errors, true
      set :show_exceptions, false
    end

    enable :sessions
    enable :prevent_request_forgery

    # Don't blow up when we can't find something
    error ActiveRecord::RecordNotFound do
      halt 404
      render 'errors/404'
    end

    error 404 do
      render 'errors/404'
    end

    error 500 do
      render 'errors/500'
    end

  end
end

UPDATE:

In the end, I found a workaround which consist in overriding the session_id, by sharing the same value for both apps, so that helper methods find the same logged in account:

Padrino.configure_apps do
  enable :sessions
  set :session_secret, 'mycustomsessionsecret'
  set :protection, :except => :path_traversal
  set :protect_from_csrf, true
  ## here starts the change, I assume first_app to be 'Admin'
  first_app = Padrino.mounted_apps.first
  if first_app
    set :session_id, "#{first_app.app_obj.session_id}"
  end
end

Every app dealing with authentication helpers must include this module:

register Padrino::Admin::AccessControl

If there's a better solution, I'd be glad to hear it, but this works for me.