EasyBib is certainly not new, it has been a staple resource for Middle and High Schools for some time now. EasyBib also offers a simplified version of its site as an Add On to Google Documents.
For Elementary students, the website option will be most useful. All a student needs to do is put in the website url, and EasyBib gives them a citation they can add to their Google Document.
In addition to websites, older students can use ISBN numbers for books and DOI numbers for journal articles. All and all a very useful tool in getting students to be responsible digital citizens.