The klarify app's location service uses Google Maps. It detects your location like any other app using location. For the app to work well, you should allow the app to access your location. You can change this in the "More" tab in "Account & data".
On Android devices, make sure that you have selected “High accuracy” for location settings. You can check this by going into Settings > Location > Location mode. Otherwise restarting the app or the phone itself might solve the problem.
If you prefer the app not to access your location, you can enter your current location manually. To do this, tap on the location icon in the top right corner on the home screen.