Kill the Newsletter! - Convert newsletters into RSS feeds
Feedbutler - Subscribe to your RSS feeds directly via email!
Listmonk - Send e-mail campaigns from a powerful dashboard. High performance and features packed into one app.
follow.it - follow.it gets publishers more followers & recurring traffic, and provides a better reading experience for followers
Reeder - Reeder is an RSS reader and client for multiple services.
FeedBlitz - FeedBlitz is a mega pack solution for social media marketing and RSS feed and subscriber integration.