How about hanging out at your local Starbucks, and offer to buy people a cup of coffee if they spend 10-15 minutes checking out your app and giving you some fee

How about hanging out at your local Starbucks, and offer to buy people a cup of coffee if they spend 10-15 minutes checking out your app and giving you some feedback? A bit scary for the introverted hacker, I admit. But I bet you get enough people to take you up on it to make it worth your while.