WhatHDR is an app that notifies you when HDR content is being played on your phone.
I noticed that even though Smart TVs popped up a notification when HDR is being played for years now, there was no such thing for Android devices. So I decided to make an app for it.
The app uses the HdrSdrRatio in order to determine if HDR is being played. Unfortunately this means the app is only compatible with certain Android 14+ devices. This doesn't mean that your device can't play HDR, it just means that this app can't detect its playback.