Trigger the camer with a blink - is there an app for this?

[alan sh]

It's sometimes awkward to trigger the camera by pressing the screen - it moves a bit. So, I thought that since the phone has a front and a back camera, would it be possible to trigger it by blinking when it's in focus? Then I thought - there MUST be an app for this. But I haven't found one yet.

So, anyone want to give it a try?

Alan