Submit your website/app to Usability Testing Exchange (UTX), then some people will do Usability Testing of it, and send you thoughts and feedback. Instead of paying, you help someone else, in exchange.
There are paid alternatives to UTX, but they tend to be expensive. UTX is free.
There are free alternatives to UTX, but at those places, you frequently won't get any meaningful help back, after you've helped others. We, however, try to ensure you'll get back actually helpful feedback, and about as much as you give: We review feedback people post. You can flag not-useful feedback, and then our freelancers will do an extra review of your website/app, in place of the not-useful review.... More Info »
UTX is social: You can ask for clarifications, and chat with others. You get feedback in text (but not as a screencast). Reviewing feedback in text is quick, and you can copy-paste it into your todo-notes.