Gone are the days of having a physical button for the camera app for Android users. There does not seem to be any manufacturers planning to develop devices with a physical camera button. Apple has graciously let the top volume bottom button as option to use as a capture button. As for Android users, there hacks available for rooted devices. But where does that leave the non-rooted Android users?
There are many lockscreens (whether stock or an app for the Play Store) that give the option of having a camera icon. But what happens if you are on the homescreen? Fortunately Android gives you options. Three ideas would be: One, to place the camera icon within the launcher. Second, one the homescreen or third use a camera widget.
With those three options you should be able to have quick access to your camera.