Stock camera apps which comes pre-installed in android phones are mostly not up to the mark and are weird and don’t have much features/options but sony’s social camera app is a app which you actually want to take good quality photos and can enjoy more features.
In our top two camera apps list sony xperia Z2 social camera is at number one position and Google Camera is at number two.
”Xperia social camera is the app which will make you surprised and bring you to totally new photography experience”
Sony xperia Z2’s social camera app is ported by xda senior member ‘vipul varma’ and can be installed on any rooted android running jellybean and above. its features include AR Effect, Motionshot, Motiongraph, Background Defocus, Wikitude places and camera widget.
You can`download Sony Xperia Social Camera App from below:
Google camera app stands at number two in our top camera app list because of its exciting features which you can used to take some brilliant photos and record your special moments in real HD resolution. This app features simple user interface, lens blur option, HDR+, Panorama shot and Photosphere. Its Lens Blur option will turn your device in mini-dslr.
This app is by Google.inc and only supports devices running on kitkat but wait we are so lucky that some experts get it workable also on JB. So we have got two links for you, one is for KK and other one is for JB.
Note that both are APK’s and can be installed on rooted/non-rooted devices.
Google Camera For KK
Google Camera For JB 
For more info and screenshots visit xda thread here