"Notify me when the crowd outside [this] stall is below 50" This situation demands the location of your device. Now, the app would hide your identity by using

"Notify me when the crowd outside [this] stall is below 50" This situation demands the location of your device. Now, the app would hide your identity by using a hash in place of your name or MAC. This is our initial solution and if something better comes up or if a more complex situation arises then we would implement something better.