Originally Posted by Eng. Mido
I installed a gallery app called QuickPic
Can I make it my default as I open gallery from camera app
If you are on stock, disabling Gallery means disabling the camera as well.
If you are on any of the 4.4 AOSP ROMs, you can disable and even remove the Gallery application without touching the camera. But even then, after the pic camera will preview the picture in it's own application.
Mostly camera applications come with their own Gallery to be accessed after you take a pic.
So in conclusion, no you can't set any gallery app as default with camera app unless the camera doesn't have it's own gallery, but for everything else you can set QuickPic as a default picture viewer.