I had a friend that got her first smartphone not long ago and loved it. Then, all of a sudden, she was complaining about blurry pics. I took one look at the phone, wiped the fingerprint off the lens, and all was well.
However, it could also be that you're juttering a bit, especially if the blur is more noticeable in low light (you'll see it more than with daylight pics). Our phones don't have image stabilization for photos, only a digital stabilization for video.