The just-released Fashism app is free to download and makes it incredibly easy to use the service. Whether you're at home, in a store dressing room, or borrowing clothes from a friend, just snap a photo and quickly upload it for instant reactions. The app (and site!) also works well for makeup and accessory questions, so ask away. The Fashism community is full of helpful advice, too; it's like having a personal assistant tucked into your pocket, and far more effective than asking your guy — again — if your new white skinny jeans make you look fat.
Earlier this year, I discovered Fashism, a site that allows your peers to help you make decisions about what to wear — just upload photos of yourself wearing the outfits in question to get the honest opinions of other users. Now, the popular site has its own iPhone app to facilitate the process!