Do you know what users struggle with your UI? Do you log which turkers can and can't use your app (eg, are they old ladies or comp sci nerds?) Turk is ok for

Do you know what users struggle with your UI? Do you log which turkers can and can't use your app (eg, are they old ladies or comp sci nerds?) Turk is ok for small traction. It's better if you simply post a link here and we'll review it. Quality testers are hard to come by.