The taking of the “selfie” is now becoming a lost art. And really, we are being serious about it. Think of it in this way: when you get to using a “monopod” just so you can take a single, shaky, self-portrait of yourself, then you know that we are quickly becoming lazy at the art of self-glamorization.
So, with that in mind, this is why this app—creatively titled as “Selfie Photo Editor - Cosmetic Beauty Camera and Facetune Makeover for Instagram”—should work very well for your purpose. In this regard, it practically acts like a photoshop editor for your selfie. If anything, this should make your “duck face” look respectable enough.