added admin part with password protected map and supporter list UNTESTED

app/controllers/admin/application_controller.rb

@@ -0,0 +1,3 @@
+class Admin::ApplicationController < ApplicationController
+  http_basic_authenticate_with name: "admin", password: ENV['ADMIN_PASSWORD'] unless Rails.env.development?
+end

app/controllers/admin/pages_controller.rb

@@ -0,0 +1,5 @@
+class Admin::PagesController < Admin::ApplicationController
+  def map
+    @supporters = Supporter.where(:coordinates.ne => nil).only(:coordinates, :support)
+  end
+end

app/controllers/admin/supporters_controller.rb

@@ -0,0 +1,5 @@
+class Admin::SupportersController < Admin::ApplicationController
+  def index
+    @supporters = Supporter.desc(:created_at)
+  end
+end

app/views/admin/supporters/index.slim

@@ -0,0 +1,21 @@
+h1 #{@supporters.count} Unterstützer
+table.table
+  tr
+    th Eingeschrieben
+    th Adresse
+    th Unterstützung
+    th width="20%" Kommentar
+  - @supporters.each do |supporter|
+    tr
+      td = distance_of_time_in_words_to_now(supporter.created_at)
+      td 
+        address
+          = "#{supporter.first_name} #{supporter.last_name}"
+          = 
+          br
+          = supporter.street
+          br
+          = "#{supporter.zip} #{supporter.city}"
+      td = supporter.support
+      td = supporter.comments
+          

config/routes.rb

@@ -5,5 +5,10 @@ Rails.application.routes.draw do
 
   get '/thanks', to: 'pages#thanks', as: :thanks
   get '/cities_autocomplete', to: 'cities_autocomplete#index', as: :cities_autocomplete
-  get '/map', to: 'pages#map', as: :map
+
+  namespace :admin do
+    get '/map', to: 'pages#map', as: :map
+
+    resources :supporters, only: :index
+  end
 end