Citation management tools allow a user to:
Mendeley is a free citation manager tool offered by Elsevier, providers of the Science Direct platform. You can download Mendeley on multiple devices and sync your citations across the devices using your online Mendeley account.
Zotero is free open source software, available for download on your computer or used online via the web. You can download on multiple devices and Zotero automatically synchronizes your data.
EndNote Basic, also known as EndNote Web, is a free web-based application offered by Clarivate Analytics and Web of Science. EndNote Basic is a stripped down version of the EndNote product that is available for purchase.