What ResearchGate does well
ResearchGate is a social platform, not a research monitoring tool. You follow authors, papers, and projects, and see activity in a feed. The platform notifies you about citations to your own work, new publications from followed authors, and papers in your fields of interest. It's good for networking and tracking specific researchers; it's less useful if you want to monitor a topic or methodology across a discipline.
Author profiles with citation tracking
Direct messaging between researchers
Easy paper upload and self-archiving
Free