Instead I just ask friends / family / people I meet in the pub to review an app and sit back and listen. Since these are "normal" people, a lot of them will be put into the mindset that you're trying to show how clever you are because you wrote an app and will instantly try and find every little thing wrong.
You have to just sit back, nod and smile, say thanks, and then pick through the feedback looking for the important bits.
In fact I believe this is a generally useful life skill. Try and listen to everyone, even if you think they're completely nuts, and sieve out the decent remarks without ego. It's not easy but I think it's important to practise.