Try this free literature review tool: PaperMap. This is a great tool to use after you finished exploring new papers. Its primary role is to organize and annotate papers you've already found. Think of it as a tool to structure and visualize your literature for research projects.
If you find a paper that fits your project's literature collection, you incorporate it into PaperMap. So when writing the literature review portion of a paper, you can simply refer to this map, trace the reasoning, and use the notes you've jotted down for each paper.
You can add as many papers as you want to your map. The tool will automatically create a citation link between the newly added paper and the existing papers in your map. The map is a transitive reduction of the citation graph, so it stays clean and manageable, even if you add a ton of papers.
Please feel free to email me if you'd like more features from this tool at saraji@g.harvard.edu!