OSF https://osf.io/ Finds papers, data, and materials. Start a project and add collaborators. Stores data, code, and other materials in OSF Storage, or connects other third-party accounts. Share papers.
Elicit https://elicit.org/ Classifies datasets. Brainstorm research questions, and search through publications.
ReciteWorks https://reciteworks.com/ Checks that your in text citations match the reference list at the end of your work. Checks that the authors and dates in the body of your work match up with the references at the end. Finds errors and checks for stylistic errors related to referencing.
Purdue OWL Writing Lab https://owl.purdue.edu/ Writing, research, and grammar and mechanics guidance.