PolyChrome is an Android app developed by Luply Apps that allows you to add color to your old black and white photos using machine learning. The app is the first and original black and white auto-coloring app on Google Play.

PolyChrome uses an AI algorithm that is not 100% accurate, but it is the best available for black and white colorization purposes. As a result, the outcome may vary from photo to photo, depending on the original quality and size. The app provides a simple and easy-to-use interface that lets you colorize your old black and white photos in just a few clicks.

The app works by opening the app, taking a photo of your old black and white picture, and sharing the result. Each photo requires one credit, and you can get three credits for free by watching an ad. You can also purchase unlimited credits for a one-time fee. The app is free to download and use, making it a great option for anyone looking to add a splash of color to their old black and white photos.