Personally, I would not agree to being tracked by an employer, unless there was a really good reason, e.g. safety concerns, as it invites abuse of power, even unintentionally.
Stuff like this exacerbates disrespect, distrust and suspicion in employer/employee relationships, in a way I believe no one benefits. Employers tend to use these tools to aggressively police minor infractions, though pretending to only want to catch the few bad apples, driving away the good employees in favour of those who think they can game the system anyway with a tit-for-tat mindset.
In the end trust is eroded, everybody is unhappy, and the underlying issues as to why those bad apples aren't doing their jobs in the first place is never resolved or even investigated.