How to subscribe to an authenticated/premium RSS feed?

To add a new Podcast into the app you will need to press on the main screen '+' button then press on RSS feed.
You will then be able to enter the podcast RSS feed url. You will have to check the 'Authentication' checkbox and enter your login / password.

After validation the app will update the podcast. You can change the login/password at any time by long pressing on the podcast, then selecting 'Custom Settings' and finally 'Edit podcast url'.