Detecting Pan Gesture End

Pan gesture end event can be detected by checking its state with UIGestureRecognizerStateEnded.

Check with the below code .

-(void) panAnim:(UIPanGestureRecognizer*) gestureRecognizer
{
   if(gestureRecognizer.state == UIGestureRecognizerStateEnded)
   {
      //All fingers are lifted.
   }
}

From Apple documentation

A panning gesture is continuous. It
begins (UIGestureRecognizerStateBegan)
when the minimum number of fingers
allowed (minimumNumberOfTouches) has
moved enough to be considered a pan.
It changes
(UIGestureRecognizerStateChanged) when
a finger moves while at least the
minimum number of fingers are pressed
down. It ends
(UIGestureRecognizerStateEnded) when
all fingers are lifted.

Read more about UIPanGestureRecognizer