Urban Adventure Quest Scavenger Hunt

This is a scavenger hunt along the freedom trail that runs directly from your smartphone.
It costs around $ 40-​$ 50 and leads to various landmarks along the freedom trail and provides a little bit of history and a puzzle at each.
It it better than just walking it but not sure it is better than a guided tour.
It claims it is for 2 – 5 smartphones but in reality it only appears to work properly when used on one: Would suggest just one person in the group reads out the clues and instructions. I think $ 20 would have been a fairer price given the bugs in the software.