Actually, an app is more likely to be on a user's phone for this kind of use... Although you can bookmark a website to your homescreen, most users don't know how to do that and even less actually do that.
A mobile app is more likely to be on hand and easy to open in case of a run-in. (Although it's not likely someone would remember to do so if something were happening)
A mobile app is more likely to be on hand and easy to open in case of a run-in. (Although it's not likely someone would remember to do so if something were happening)