Tumblr Savior is an app (or website) that helps users filter out unwanted content on the popular blogging platform, Tumblr. It allows users to blacklist certain words, phrases, or URLs and then automatically filter them out when they appear in the user's dashboard or timeline. The app also allows users to whitelist certain words, phrases, or URLs in order to make sure they are not filtered out. This helps users to avoid seeing content that they find offensive or don't want to view. With Tumblr Savior, users can filter out explicit content, political content, and content from specific blogs or users.
New XKit
BBoostr.com
It works with tumblr and performs the desired function. As far as I can tell, these other options do not.