The CRORx application is designed to assist railway professionals and enthusiasts in decoding triple-head signal aspects according to the Canadian Rail Operating Rules (CROR), based on the version effective January 28, 2025.

To use the app, tap any light to cycle through its available colors and flashing states. You can also tap on plates to toggle them on or off, if they are permitted by the current signal aspect.

Once the desired signal combination is selected, tap the "Decode" button to interpret the aspect. Use the "Reset" button to clear the current configuration and start a new one.

This tool operates entirely offline and does not require any device permissions, either at installation or during runtime. It is free to use. If you find it helpful, consider supporting it with a PayPal donation.

The CRORx App is hosted on GitHub. You will see a warning saying it may be harmful. It's a standard warning when a hosting site doesn't scan a file for viruses. The file itself is safe to download. However, before installing it, you may want to use an online virus scanner such as
Virus Total.

Version 1.2.0 - August 6, 2025