The MCT does not have an app, but you can check the MCT route on Google Maps.

Online Map, GPS Data: https://mct-a.org/en/hike/route/web/

You can also download map data (GPX files) meant to be used as a supplement to the Map Books from the link listed above. Download the GPX data to your smartphone and use any smartphone app you like that can use GPX files to check the trail route and your current location as you hike. (For app installation instructions, please see the official documentation for your app). See the notes on the webpage above for details on how to use the map data.

Please keep in mind that smartphones don’t always work properly. They can run out of batteries, be damaged or lost or lose reception in some areas, so please prepare accordingly.