Wireless 2-sensor fridge thermometer?

I have tried a number of different wireless 2 channel (fridge body & freezer) thermometers, and after having most of them fail, often still giving the last reading on the display when the sensor died, I switched to a pair of Sensor Push devices. No display - reads on your phone. Provides instant / hour / day / week / month graphs of temperature & humidity. Expensive, but they work. I now have 4 sensors, 2 for the refrigerator, one for outside temperature & one I keep in my medicine storage box.