My newest NPM module – ember-notification-hub lets you embed a small notification center into your ember app pages. It persists notifications across sessions in local storage until cleared and allows you to pass a promise to the notification hub which will display the notification as pending until completed (when the promise resolves). It looks sort of like this:
The center pops open when there are active notifications and the user is able to open or close the hub at any time. The package is free to use and MIT licensed. Cheers!
You can read more about it on the package’s github page.