A video doorbell is one of the easiest cases to argue for a smart-home upgrade — you want to know who is at the door, you want a clip when something arrives, and you want to be able to look at the porch from your phone without driving home. The hardware industry has answered with a Cambrian explosion of brands: Ring, Nest, Eufy, Aqara, Reolink, Arlo, Wyze, Blink, and a hundred white-label clones on Amazon. Almost all of them want $80–$250 up front and $30–$100/year for cloud video storage. If you have an old Android phone in a drawer — and most of us do — you already own a better doorbell than what Amazon will ship you. That phone has a 12 MP camera, a microphone, dual-band Wi-Fi, USB-C continuous power, and a CPU that is roughly six times more powerful than the SoC in a $200 Ring. The thing it does not have is doorbell software. That is what this article is about. Below is a real, honest comparison of the five Android apps that can credibly turn that drawer phone into a doorbell.…