I mentioned consent to cover 18+ "kids". What I said is that if they know about it it's always ok (because they're consenting, so there's definitely no issue.). If they're over 18 and they don't consent, I feel like that should be illegal, but I don't know for sure. If they're under 18, I'm pretty sure they don't need to consent, since parents can basically make them do whatever.
So we deliberately designed the system to be 2-way - both parents and kids need to consent and are aware that their location is being broadcast.
Additionally, on iPhone you can always tell when location services are running as there's an arrow that appears in the top bar. You can also see in Settings->General->Location Services which applications are using it.
How do you handle the following edge cases
1) a kid using the product grows over 18 while the product is still installed on their phone?
2) Does a person being monitored get some visual feedback about the fact that theyre being tracked ?
It's really up to the families - if they are ok with sharing location data then they can keep it running. It seems like this would be most useful when the kids are 12 to 14 years old.
We have very plans for products that extend up and down the age range, but this isn't it.
2) All parties on the system get the same visibility; you can see your own history and your parent's history in the same way that they can see yours.
We've really tried hard to make the app useful to both parents and kids.
Cool! It looks like youve put in a lot of thought about the privacy and social issues - which is always a good sign for someone doing a privacy related startup.
If the kids are over 18 and you were to track them without their knowledge, that might be illegal.