I'm not in North America, but here in South America, they are definitely after revenue. I'm usually very respectful when it comes to speed limits. The only speeding ticket I got was driving by a big avenue. Basically, there's an elementary school near this avenue so logically there's a lower limit in that area. I went over the limit by 17 KM/H on a friday night (clearly no children could be around). Next block I get pulled over and get a very juicy ticket, they were obviously fishing.
I'm not familiar with the application, but from the article it's implied that it can be used to avoid sobriety check points. I don't see how this helps improve safety at all.