There is nothing to download from an app store. You install it from your browser, and it then behaves like any other app — its own icon, full screen, no address bar.
- Sign in on your phone.
- Go to Settings from the More menu.
- Use the install option there, or your browser's Add to Home Screen.
- Open it from the new icon from then on, not from your browser.
Working with no signal
The app keeps working in a dead spot. Status changes and trip completions you make offline are saved on the phone and sent up as soon as you have signal again. You will see a note telling you something is saved and waiting. Do not sign out with work still queued — signing out clears it.