It was $13. Be interesting to mess around with it and maybe hack it a bit.
The tech behind it is cool. It’s essentially a light source that can detect the pulse and oxygen content of the blood in your finger.
I’ve had one attached to me twice in my life – once when I came down with strep throat, once when I had my wisdom teeth out.
I just think it’s fascinating that the technology is now available for $13 U.S. Amazing.
Spewing Truth in the face of Lies 
The Apple Watch uses similar tech to determine your pulse, I believe. The sensors are built into the back of the watch. They say it may not work well if you have a tattoo there.
Yeah I know – except the Apple watch is several orders of magnitude more expensive than the unit I purchased.
By now I would have thought ‘there is an app for that’