Hald CLUT files offer a quick and easy way to apply effects to photos, and there are plenty of desktop applications that can handle the task. But if you want to use your favorite Hald CLUT files on an Android device, you'll quickly discover that there are not that many apps (if any at all) that allow you to do that. No problem: instead of relying on a third-party proprietary app, you can roll out your own solution using Termux.
Start with installing Termux, Termux:API, Termux:Widget either from Google Play Store or F-Droid on your Android device. Launch Termux and run the following commands:
pkg update pkg upgrade pkg install termux-api wget imagemagick termux-setup-storage
Next, install the hald-clut.sh Bash shell script:
cd .shortcuts wget https://raw.githubusercontent.com/dmpop/termux-scripts/main/hald-clut.sh chmod +x hald-clut.sh
On your Android device, create a folder, and copy the desired Hald CLUT files into it. Add the Termux widget to the home screen, and you should see the hald clut.sh entry in the widget. Tap it, pick the photo you want to process, choose the desired Hald CLUT file, and you'll find the resulting image in the DCIM/HCLUT directory.