Firecracker is the only program that helps you remember in the long term what you are learning. Many students use First Aid as well, and Firecracker provides page numbers for reference (in-line citations) in the newest edition. You can even search our related page number by which other review resources you're using in our citation search engine: labs.firecracker.me/search
Some of the most successful doctors-to-be use Firecracker throughout medical school to complement their coursework, and use a dedicated exam prep tool alongside Firecracker in the weeks leading up to their Step date. Therefore, to make sure you don’t forget your hard-won knowledge come exam day, Firecracker is an essential component of your study efforts, regardless of what other books, courses, questions banks, etc. you may choose to use. In fact, Firecracker will help you get the most out of any of these resources, not only by helping you identify and retain the material they will need to know for your standardized exams, but also because it will save you time by saving you from having to relearn things you would otherwise forget.
All of Firecracker's content is originally authored, so our questions will not overlap with any other resources you may be using. Doing a high volume of unique questions is one of the most important keys to successful test preparation. We've polled our membership, and found the most popular resources to use alongside Firecracker are First Aid, UWorld, and Pathoma: http://blog.firecracker.me/students/tools-for-dedicated-prep-part-1