Having a phone in the jersey pocket is an essential piece of equipment for me. I ride with one spare tube, a couple of patches and one Co2. If not for the phone I would carry a pump as well. Fortunately I haven't had to make The Call due to mechanical issues yet. I did have to call for a pick-up when I had a stabbing pain in an inflamed Achilles about 10 miles from home.

Two of my favorite cycling apps are Strava and Road ID. Road ID is useful for a couple of reasons. 1. It sends an email or text to your designated recipients letting them know your going out for a ride. They are then able to see where you are at on the map, in real time, until the ride is over. If you stop moving for 5 minutes it will send them a notice letting them know you haven't moved. It will alert the rider at 4 minutes letting them know the emergency alert is going out in 1 minute. This gives you the opportunity to cancel the alert avoiding any false alarms. 2. It turns the phone's lock screen (iPhone) into an information panel. You can show emergency contact phone numbers, blood type, allergies, etc., which a first responder could see.