This is VERY different than what your friend is doing. Your friend is reporting these drivers to law enforcement and allowing them to deal with it, and/or allowing your friend to appear before the people he's accusing in court for the purposes of issuing and enforcing a citation in regards to a violation of the law ensuring due process. This app reports directly to the DMV and insurance companies according to the article.
Your friend is doing it right, the app is doing it wrong.
Your friend is doing it right, the app is doing it wrong.