Scite.ai is a tool that mainly focuses on evaluating the reliability of scientific claims. The company uses proprietary deep learning algorithms and natural language processing techniques to develop what they call a "smart citation index" (or scite) that categorizes citations based on context. This allows researchers to analyze the citation context of a paper to determine if the citation supports or disputes the cited claim.
While it does not directly provide summaries of papers like many other tools do, it can be a useful tool for evaluating the credibility of the research you find. In addition, the tool can be used to claim your own papers and see who is citing them.
Data Sources: Scite gets their citations from a wide variety of sources and relies heavily on agreements with publishers. For more information see their FAQ about where they get their articles from, and their list of journals.
Cost: Scite currently costs $20 a month for an individual subscription.