thanks for the feedback. This is a quite common request.
The main reason I have not implemented this feature for SimpleViewer is that it would involve adding a new set of controls (play/pause) that I feel would distract from the main purpose of SimpleViewer - to display images in as simple and unobtrusive manner as possible.
Personally I don't find automatic slideshows to be very useful. Basically you are letting the computer decide when you view the next image. When given an easy way to click next, does anyone actually wait for the timer to complete? What if you are studying an interesting image and the timer decides you now have to look at the next image?
Auto slideshows do have a place in certain situations. I built AutoViewer to address these situations.
SimpleViewer Support Team.