Does the watch run without the mobile phone, e.g. can I go jogging for 1 hour with just the watch music and bluetooth headphones without the mobile phone? Or does everything only run when the mobile phone is with it?
The watch shows the time even when the mobile phone is not nearby. Timer, stopwatch, date display, heart rate measurement, fitness and training also work.
Without the mobile phone, connect challenges, commute time, music control, notifications and weather display do NOT work.
The watch itself cannot store music and therefore cannot play music. You cannot connect headphones to the watch. The watch can only control music playback on the mobile phone (louder/quieter, previous/next song, play/pause).
So you can go jogging until the watch battery runs out and your steps and heart rate are recorded. When you return from your jog and get back to your phone, you can sync via the app on your phone and see the training info in the app.
To listen to music, however, you need to use another device. The watch cannot play music.