First thing to check: If you’re using OS4.0, go into your device’s Settings -> General -> Location, then check that Location Services is switched on and, specifically, that the Lonely Planet section is switched on. NB: Subsequently clicking ‘Don’t allow’ when asked by an LP app to use your current location will reset your Settings and you’ll need to go back in and switch it back on. 

Locate Me uses GPS or triangulation technology (depending on your device), which can work offline but is finicky. It requires a clear patch of sky above you so five-seven satellites can align and sort out where you are. We have found that our users have difficulty in dense cities (like New York) to get it going.  To speed it along, you need to turn on data roaming to let the phone know that you are in a new city. 

Once you’re at your chosen destination, hopefully with your luggage:
1. Turn data roaming on.
2. Open your Lonely Planet Travel Guides app and go to the 'map' section.
3. Wait for the Locate Me function to locate you.This may take some time due to triangulation of mobile signal, cloud cover, satellite positioning, pigeons overhead ...
4. Close your app.
5. Turn data roaming off. Please don’t forget this step!
6. Open your Lonely Planet Travel Guides app again. Locate Me will now work (although, unfortunately, not perfectly in some cases).

We can't promise there won’t be any charges from your mobile carrier. But in everyone’s experience so far - from our own group of testers to travellers in many varied destinations - no one has been charged.