If one place is deemed to be safe, everyone playing will go there: consider how to split safe places among participants based on their usual environments to avoid clogging a spot when an emergency happens Consider a real-time alert system via app that reminds you where to go

Needs a very good and inexpensive go-to-market strategy. Might perhaps work better bolted on to existing apps such as PokemonGo that already have a lot of market traction.

Really interesting idea (Thinking outside the box for how to tackle terrorism) and you guys executed it really well in the time frame, especially considering you hadn't done any AR before! Kudos for the Harry Potter theme and well done.