The service is owned by Google and the only one of its kind.
FeedBurner skips through RSS feeds, correcting small errors in them and adding functionality, for example. The Play button for podcasts.
Also provides statistics on subscriptions to the RSS feed.
GovTrackUse RSS to track government.
FeedMyInboxEnter the address of the page and our mail, and get RSS-feeds as a mailing.
Choose how often: immediately, once a day, per hour ...