The Flipdish mobile applications adapt to your users, showing them relevant information to them (like the closest stores to them), in their relevant language.
The apps check the region that the phone is set to and displays the appropriate language and unit of distance. This means that it's not possible to specify exactly whether your users see miles or kilometres in your app, they'll simply see what's relevant to them.
To see this in action, you can change your region on your device and see it update.
To update your region on iOS, navigate to Settings -> Language & Region -> Region, and update to what you like. In the example below, I'm switching from UK to Ireland to see how it changes the unit of distance used.
It'll be a little different depending on your version of Android, but look for "language settings" in your phone's settings, and make changes there. You should see a difference like below when you change.
What regions have which distance unit?
If you set your region to United States and United Kingdom, then the unit used will be miles(m).
For all other regions, the unit used is kilometres(km).