My stock camera app on Jellybean only takes one shot, and that is when I left up on the button. If I keep it down it locks the settings but doesn't take the picture until released.
Hope this helps,
Good Luck!

 

Your post got me to look into this, since I experienced this annoying 'feature' the other day and wanted to know what was going on.

If you look under Settings, you'll see a selection for "Burst shot". Set this to Off and you'll be able to press and hold to focus without the camera starting to take loads of shots. Why it's possible to set Single shot and then have this overridden by Burst shot, I have no idea.

 

Yep, I had the same problem whilst set to Single Shot. My point was that there's a separate setting which overrides this... the "Burst Mode" toggle in the Settings menu. Set Burst Mode to Off and Single Shot starts behaving as expected.

But great if you've solved the issue - I just want to clarify this in case anyone else experiences the same thing.