text: However, texting while driving is just stupid. There have been several occasions where police have recovered cell phones after a car crash and the Snapchat application was open and the speed detector filter was active. The fastest speed ever recorded on the app was 121.2mph. There have been cases where people have died at only 10 mph. A lot of people text while they are stopped at a traffic light, but even then it is dangerous because you are not being wary of your surroundings.