phone apps for troubling times

I'm not particularly concerned for myself. I am worried, however, about the care and feeding of my cat, should anything ever happen to me. As I've mentioned before, I'm not on the first list that my federal government is pursuing now, but I will be on their second and third lists.

• I saw the news stories like this one about the "Are You Dead?" app. I thought, "That's perfect!" I tried to download it, but apparently it's only on iPhones but not Android.
• I discovered that all Android phones have Google's own Personal Safety app. Maybe it's because of all the trying-to-be-helpful training options showing up everywhere, but the user interface is really awful. Even this explanatory article seems really long. I'm not sure I'd be able to use it in a hurry. I promise to make an attempt today to set it up, though.
• I just downloaded the ReadyNow app from Human Rights First. It's straightforward, and I plan to configure it completely for my own needs today. It is, however, another "active" tool instead of a "passive" tool that I also need to arrange.

Question: What is a good "dead man's switch" that will send an email if I fail to respond within 48 hours? I figure that's long enough that my cat won't suffer ill health without her usual daily feeding of special food.