The app itself is poorly designed, allowing you to register but logging you out randomly afterwards. The set up process seems like a loop, with you going through their Learn more option and then finishing all of their tips before closing it and being presented with the option to go through it again.
No where did I see any sort of actual emergency button, there was a white circle that I tried pressing but it didnt seem to accomplish much. After scouring the app for a moment to see where the actual function was, I dropped the app altogether.
The concept itself is spot on- I fully support this. So please upgrade your app to help keep people safe.