This is a massage tool with ribs or ridges that you roll the foot over. It was designed by a podiatrist. Many people find it helpful for plantar fasciitis and those feet that are tired at the end of the day.
These are a splint or brace that you wear at night that are supposed to correct bunions. There is some debate if they do correct them or not, but the research shows that they can improve the angle of the big toe by a few degrees after a month of use.
Barefoot running was a fad a few years ago. It was somewhat controversial due to all the claims that were made for. It turned out once the science was done, the benefits were just not there and runners have lost interest in it.
Pain in the ball of the foot can be many different things, ranging from a plantar plate dysfunction, to a stress fracture to a mortons neuroma. Sometime the differential is easy and sometimes it is difficult. Getting it right is so important as each cause of ball-of-foot-pain has a different treatment.