Review on Lixada 4g Ultra-Small Wireless BT & ANT+ Bike Cadence Sensor: IPX7 Waterproof Speedometer & Computer by Gilbert Pfaff

Bought a few months ago. I'm trying to use it with the Urban Biker Android app on my Samsung S7 Edge over an Ant+ connection. The app recognizes the sensor but never gets the cadence. I thought it might be the battery and in fact the built in one was dead. The spare part has been checked well, but the cadence values are still missing. After further experimentation I found that I only get a good sensor signal in the app if I hold the sensor about 2.5 cm away from the phone - that won't work! The $12 I spent isn't worth a refund and I have to say the price is suspiciously cheap. I'm wondering if they sell devices that didn't pass quality control? My advice is to spend a few bucks more and get the full version.