There are several free AI tools available for students to aid in their studying. Some of the best options include Dende AI, Doctrina AI, ExamCram, and Socratic. These tools offer a range of features such as quiz generation, flashcard creation, and interactive learning platforms. Additionally, tools like Grammarly and Quillbot can help students improve their writing skills and paraphrase text. It's important to note that the best AI tool for studying may vary depending on individual needs and preferences, so it's worth exploring multiple options to find the one that works best.