Brain Sensei courses are all online and self-paced you can take as long as you like (within your subscription period). This means, there’s no instructor, but this doesn’t mean you’re on your own. Reach out to them by clicking the big red help button on every page of their site or at contact@brainsensei.com if you’re struggling with a question or any part of the course.
Both their CAPM and PMP exam prep courses are packed with a huge amount of material as well as 4 full practice exams. You can take and re-take any part of the course as many times as you like within your 180 days (6 months) access period.
Their belief is that the interactivity they've built into the online experience provides for better retention of the material and an increased chance of passing the exam (not to mention it makes the material much more interesting).