Some setup you must do manually if you haven't yet:

1. Ensure you have defined default url options in your environments files. Here
   is an example of default_url_options appropriate for a development environment
   in config/environments/development.rb:

     config.action_mailer.default_url_options = { host: 'localhost', port: 3000 }

   In production, :host should be set to the actual host of your application.

2. Setup your target model (e.g. app/models/user.rb)

 - Add including statement and acts_as_target definition to your target model

     acts_as_target email: :email, email_allowed: :confirmed_at

 - Add notification routing to config/routes.rb

     (simply)      notify_to :users
     (with devise) notify_to :users, with_devise: :users

 - You can override several methods in your target model

     e.g. notification_index, notification_email_allowed?

3. Setup your notifiable model (e.g. app/models/comment.rb)

  - Add including statement and acts_as_notifiable definition to your notifiable model

     acts_as_notifiable :users,
       targets: :custom_notification_users,
       group: :article,
       notifier: :user,
       email_allowed: :custom_notification_email_to_users_allowed?,
       notifiable_path: :custom_notifiable_path

 - You can override several methods in your notifiable model

     e.g. notifiable_path, notification_email_allowed?

4. You can copy ActivityNotification views (for customization) to your app by running:

     rails g activity_notification:views

5. You can customize locale file which is generated as following file:

     config/locals/activity_notification.en.yml