I've noticed that no TFRs show up in iFly unless it's zoomed in tighter than about 250 nm across the screen of my iPhone in portrait mode. That's fine for planning flights shorter than a couple of hundred miles. But it's not good for longer flights (or when trying to guess where the president is going tomorrow).
So I'd really like for that visibility distance to be user-selectable. (Of course, if it already is and I've just missed it, please let me know how to find it.)