a few ideas
1) Inspired by an App called Companion which is an aid for someone uncomfortable walking alone, a bracelet that measures pulse. When the pulse speed up dramatically it would make loud noises and alert the police. It could also have a GPS like the app, so your location could be shared with a friend or the police if alerted.
2) Shoulder messaging backpack or side bag. Wearing backpacks/ purse to school, work, or shopping often bothers my shoulder and this would be helpful to me.
3) More of a vague idea, but I would like to combine clothing and lighting. I was intrigued by the raincoat but maybe lights could be combined with clothing to light up streets or be used when the power goes off.