Go with the user flow
River is an application for requesting feedback on user flow within your application. Users may specify initial setup and the task they want evaluators to achieve, then send a link. Evaluators then go to the link, and as they attempt to go from the initial setup to the end goal, note places where application is useful to the end goal, where steps are confusing, and where the evaluator didn't know what to do next to accomplish the stated end goal.