var app = angular.module('plunker', ['ui.bootstrap']);

app.controller('MainCtrl', function($scope) {
  
  $scope.params = {};
  
  $scope.clearText = function() {
    $scope.params.text = null;
  }
  
});
<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <script data-require="angular.js@1.4.x" src="https://code.angularjs.org/1.4.9/angular.js" data-semver="1.4.9"></script>
    <script src="//angular-ui.github.io/bootstrap/ui-bootstrap-tpls-1.3.3.js"></script>
    <link href="//netdna.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet">
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl">
    
    <div style="margin: 20px; max-width: 500px;">
    
      <div class="form-group has-feedback">
        <label>text box</label>
        <input type="text"
               ng-model="params.text"
               class="form-control"
               placeholder="type something here...">
        <span ng-if="params.text"
              ng-click="clearText()"
              class="glyphicon glyphicon-remove form-control-feedback" 
              style="cursor: pointer; pointer-events: all;"
              uib-tooltip="clear">
        </span>
      </div>
      
    </div>
    
  </body>

</html>
/* Put your css in here */