Bests & Worsts Reviews from Amazon

Bought this for my mother who lives next door. Easily set up contacts, and testing went smoothly and easily. I tested it over the next several days and it worked. On my phone and my mothers the App was active,connected and working. Three weeks later, last night, my mother was not feeling well and I said lets test to ensure it is working AND IT WAS NOT! On my phone and my mothers it looked no different than when we ran the tests -the app was on and working. but when she presses the button, it did not work. We tried several times and nothing. I had kept the original packaging and instructions, and I coudl not solve. There is no phone number or chat to contact anyone to assist. I went to the site and the FAQ's dont provide how to solve. Amazon did call me after I requested so via the refund process and they could not solve either. VERY DISAPPOINTED AND MORE IMPORTANTLY - IN MY OPINION DANGEROUS!