They are provided by your auto insurance company. A potential privacy nightmare, they track your movement. They also can get you a much lower rate.

If you don't want to go through your insurance company you can check out an app we built called RoadClub. You get points for safe driving behavior - and you can get the hard brake alerts. Is it a bit annoying? yes. You can't just drive agressively - you need to give space to slow down. I still struggle with it.