Yes, but it doesn't work too well in the shower.
Cyrano/Mike/All--I can't speak to the alert button on a chain issue other than to say that I knew an 19 year old, Div I College Football player in the prime of his life (and completely sober) slip and fall in the shower, hit his head and fall so as to cover the drain. He was out long enough for the water to almost start to cover his nose and mouth and they were turned upwards. Another athlete found him and dragged him off the drain.
Get on the CDC web-site, and I believe household accidents like that are at the top of the list of injuries and deaths. So I think one of these warning devices is an excellent idea. Frankly, I think it takes one hell of a man to admit, "hey I may need some help."
As to the cell phone in the shower issue, you all need to check out Lifeproof cell phone cases.
Waterproof iPhone 7 cases from LifeProof | Live LifeProof | LifeProof. I don't know your type of phone, so I just
copied the link to what I use on mine. These are the best invention since sliced-bread.
In fact, I washed my cell phone last night in hot water and dishwashing liquid because I have been spraying herbicide all week. Even from a sealed tractor cab with chemical filters, that stuff gets everywhere and is dangerous to have on you.
I have dropped my cell phone from a Cat D-6T dozer cab and a 175 hp tractor cab (that's a tall cab) onto a concrete floor and never had a problem.
You may want to check them out where you can take your phone anywhere.