var jsonString = '{"name":"tom","age":22}';

var jsonData = JSON.parse(jsonString);

$scope.arr = [];

for(var k in jsonData){

    $scope.arr.push({key:k,value:jsonData[k]});

} 

<ul>

    <li ng-repeat="item in arr">

        <span>{{item.key}}</span>:<span>{{item.value}}</span>

    </li>

</ul>