This is an extension for the Chrome browser. 

You can choose from two different types of filters. One is a keyword filter, which is used to hide Tweets that contain a certain word.

You can choose from one of two categories of phrases: phrases that start a tweet, or phrases that can occur anywhere within a tweet.

You can specify a maximum of two different lists of phrases. The keyword filter and phrase filter are both controlled by a tab in the settings of the extension.

The settings contain the phrases that are shown, and what happens when you click a link.

When you view a tweet, it is now possible to see the phrase that was matched.

If you would like to hide a tweet, you can do that by clicking the X in the top right corner of the screen. If you would like to view a tweet again, you can do that by clicking on the link in the settings.