mark search string dynamically using angular.js

How can I mark my search pattern dynamically in my html?
Example:

I'm using angular and my html looks like this:

<div>
   <input type="text" ng-model="viewmodel.searchString"/>
   <!--Moving over all phrases-->
   <div ng-repeat="phrase in viewmodel.Phrases">
        {{phrase.title}}            
   </div>
</div>

I want the string matching pattern will be mark on every change in search string.

Can you help me?