Nice, @Gunner. That is effectively what I did, but I used alternating hearts (for a heartbeat), and a slower cycle. Note that there are differences in appearance, even among android devices. The heartbeat idea I had was tough, because there are few hearts exactly the same size. This creates shifting of the text if the emoji appears first, and also resizing if the width of the value field is constricting. I found it easiest to alternate a red heart with a blank, and append it to the end of the "up-time" display, instead of the beginning. Then make sure the value field is wide enough to handle any realistic up-time display. Also, when larger emoji's reach full height (happens when text is not constrained by the box) their tops get cut off by the field label, even if the label is " ".
@Costas, I have not tried on IOS, and my wife is out of town with our only IOS devices.
It would be good if someone that has both iOS and Android devices in multiple versions could post screenshots and codes, but that is a lot of work to ask of anyone. Further, it would be good to have a header of constants/#defines containing these values.