Nice. What I would like to see is having swipe and onion skin modes working without dragging the slider: just move your mouse over images and get swipe position

Nice. What I would like to see is having swipe and onion skin modes working without dragging the slider: just move your mouse over images and get swipe position move along or opacity change accordingly. Of course, sliders should still be there—and make them bigger, Fitt's law, you know. Probably some more prominent indication for opacity would not hurt too.