Readerrr's interaction for subscribing to feeds

If a user hasn't yet subscribed to any feeds or has just signed up, they see this welcome screen with an invitation to subscribe to some feeds. On narrower screens, when the sidebar is hidden by default, clicking "subscribe" button opens the sidebar and indicates what a user should do next. This also teaches users how to subscribe to feeds later when the welcome screen is replaced with the feed content.

Readerrr is a RSS reader.