To install run: rails g notifun:install
This will generate three things:
The config initializer at config/initializers/notifun.rb.
The migration to create the notifun tables.
The json file for loading message templates at config/notifun_templates.json.
Once installed, edit config/notifun_templates.json to add your message templates.
You can edit them at /notifun/message_templates.
You can see the generated messages at /notifun/messages.
Users can edit their preferences at /notifun/preferences.
rails g notifun:install can also be used to install missing fields after updates.