Camera ZOOM FX is really good, although it isn't free it is 50% of in the Play Store right now so it's only $1.49 and there are lots of free composition packs available as well. This is kind of the definitive Android awesome camera app by most "Android Experts" like Lifehacker, SlashGear, and Gizmodo (if that means anything too you)
Camera360 is pretty good too and free, and you can get lots of plug-ins for various effects free in the Play Store too.
If you are mainly into just sharing photos on Facebook or Instagram, consider Pudding Camera, it is really nice but has a maximum resolution of 2048x1536 (they call it 1280dpi resolution) it isn't the best for high quality printable photos, but excellent for online sharing.
Best bet though it to try several, and stick with the one you like the best and works for your usage of the camera.