Scite AI ($20/month): Assistant answers questions and provides citations (including in-text citations). What makes this tool different is that it provides context for the citations. It is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
Connected Papers (Freemium): Using a single article, Connected Papers creates a graph of related papers. The positioning of the citation indicates the amount of similarity, even if the papers don't cite each other. It can also be used to identify prior works cited in the graph (which are likely seminal works) and derivative works. Connected Papers is linked to Semantic Scholar.
Elicit (Pay with Credits): Elicit helps identify literature and summarizes articles. This tool is a little different from the others because it uses a "notebook" format to keep track of your research. The three options you have to start are: Find Papers, Extract Data from PDFs, or List of Concepts, and then further refinement is possible to Select specific papers from your table (or multiple tables) to create a new table with just those papers, Summarize the abstracts of specific papers you select, or Chat with papers you select. Elicit's YouTube channel has demos, tricks, and tips to help you get started.
Litmaps (Freemium): Similar to Research Rabbit, Litmaps provides a visualization of a literature review. However, the free version is a little limited and only allows for one map. The about us page on the website provides some examples of how the tool can be used.
Worldcat (Free): Using third-party AI technology, Worldcat now has an "explore similar titles option" that provides book recommendations using just the title and author of the book you are viewing. For more information, click here.