Valuable Cell Phone App: Traditional Latin Mass Finder (iPhone & Android)
The 2 combined images below (left & right) are from the Average Catholic blog and show screenshots of the iPhone version.
This is a link to the Google store showing the Android version with more detail.
I downloaded the app and tested it and the app found TLMs both near and far. The app has an email address and relies on feedback from users for correcting errors and/or adding updates. Try it... It's free. Nothing like a good road test!