Get back to where you started from.
You might also be interested in Get Back in Time.
Long-press any button on the right side of your Pebble watch to set the target (current) location.
After you have set the target location, the app will wait for location updates from the phone.
When you move away from the target, the ring should show you the compass direction you should head to in order to get back. The numbers should show distance (in meters or kilometers).
If you are not moving or your phone is not registering your movement, nothing happens in the Watch App. (Especially indoors the location of the phone will often not update at all.) If the watch doesn't show your location or movement correctly, you can try to test the location capability of your phone with another Pebble app.
If the watch shows a small C in the lower right corner of the screen, the compass is being calibrated. Move your wrist around to help your Pebble with calibration. Small F means you're nearly there, the compass is being fine-tuned. If there is no character in the lower right corner, the compass is calibrated and the arrow in the ring shows you the direction to find your target.