How is this different from free question lists online?

Free question lists are usually static — you read through them once, maybe check answers at the bottom, and there's no way to track what you actually know versus what you're guessing on.

Examerio turns that into an active practice loop: each session pulls a random set of questions, you get instant feedback on every answer, and your accuracy and progress are tracked over time so you can see exactly where you're weak before the real exam.