def pick_app(&block)
  require_user

  if app = app_from_dot_ninefold_file || app_from_env_id
    block.call app
  else
    load_apps do |apps|

      if apps.count > 1
        if app = interaction(:pickapp, apps)
          save_app_in_dot_ninefold_file(app)
          block.call app
        end
      elsif apps.count == 1
        say "▸ You have only one app (#{apps[0].name}) proceeding...", :yellow
        block.call apps.first
      else
        puts "You don't have any apps"
      end
    end
  end
end