This could be helpful to some

I have Windows phone, so this won't help me either, but still, a lot of people can use this

They may be working on putting it on other platforms. Typically apps first become available to the iPhone app store and Google Play before any others.

Google Play is easier to code for and Apple is really popular

Fair, but like if the abuser is about to come at you and you were on your phone before that you'd still have time to hit the button.

I'm not knocking it, sounds good. Perhaps after he or she has calmed down. Many times the abuser treats the victim as a prisoner but will still let them on the phone as long as they "obey."