In my opinion this is a silly investment and constitutes MORE weight in your pack already laden with stuff that (I promise you) will end up in hiker boxes over the first 200 miles if you were to actually pack it.
Yeah - totally skip the spot. People have only started carrying cell phones in the last 10 years or so. I see you have one - you'll get service in about 60% of the places you'll be or be within a mile walk of service.
I know you think we're being hard on you but getting the right stuff, pared down, super organized is what you want to do. Get that first aid kit in a quart zip-lock. If you need extra bandaids there are plenty of stores along the way.
Get your pack weight (total, not base weight) to a MAX of 1/4 your body weight. If you are an 18 year old gal and weigh 110, that's 27.5 pounds including a food bag and water.
You can do it!!!