I use Imagine for image viewing. It has an amazing little feature: when you press the "Next Image" (or "Previous Image") button and the window resizes/moves to

I use Imagine for image viewing. It has an amazing little feature: when you press the "Next Image" (or "Previous Image") button and the window resizes/moves to keep its size consistent with the new image's size, the mouse cursor is automatically moved to still be over that "Next"/"Previous" button. It most likely takes about 5 lines of code to implement but what's important that the author actually thought about and took care about this scenario.