Topic says it. The current test version of the RP app for iOS supports streaming directly from music in a cached playlist in the Apple Watch (without phone present around and no need for GSM version). The thing works to the best of my knowledge, but it's a tricky piece of software that needs extensive testing so beta testers are very welcome.

To access the test just follow the link to TestFlight from the iPhone and follow instructions there. You can always remove yourself from the test, just reload the _normal_ app from the App Store app (and remove yourself from the beta using the TestFlight app). In the TestFlight app you can also tailor the amount of notifications (and if you want notifications in email).

The new version of the app allows you to move a cached playlist from the phone to the watch and then play the cached playlist from the watch directly. Just open the cache manager, select a playlist and then the "To Watch" button below.

Warnings, requirements and limitations:
- It's a beta build. It definitely will have some problems. It basically works, but the watch part is beta. The iOS part is basically unchanged from the current version, so I don't expect any problem.
- The watchOS app requires WatchOS 5 (sorry series 1 users, but it's a requirement for audio).
- Only one cached playlist can be moved to the watch and it will be deleted from the phone (to avoid you listening twice to the same songs).
- Copying the playlist to the watch can be _really_ long, and there is no control at all, nor feedback (sorry, no way the app can know what's happening to the copy)... it will be copied when iOS/watchOS think it's a good moment to do it. My worst case at the moment is during the night while recharging after asking the copy in the morning. This is no different from what happens in the Apple's Music app in itself: you ask to copy a playlist/album to the watch and the copy will happen... sometime in the future.
- Playing from watch _requires_ a bluetooth device/earphones paired with the watch.
- bitrate in the phone should be limited to the "medium" one (64 Kbps AAC+), I've not been able to transfer an "high bitrate" playlist and I suspect it could be downsampled during the copy. YMMV, make some test, but start your tests with "low" or "medium" bitrate to avoid starting with a frustrating experience (copying is already long enough).
- again: copying the playlist can last for hours... please do not transfer an enormous playlist... start small (say a couple hours or less). The time will increase if you try to transfer multiple playlists and it cannot be really aborted, so please don't make multiple transfers out of frustration, this will only worsen the situation. Remember also that the watch is VERY limited in available space (4 or 8 GB) so keep this in mind.
- Yes I know, those transfer limitations are boring... may be next watchOS version will give us better options, but meanwhile that's what we have to work with... remember is a watch and that the fact you can stream music (and RP!) from it is already an half-miracle.

Please use the feedback option of the iOS app (or the forums) for feedback and bug reports. If you have a problem on the watch, please send us the phone logs... Force press the app on the watch and select "Send Logs" from the menu. After some minutes, _on iOS_ select settings > feedback > malfunction and send us an email with the logs (there will be an additional phone-log.bz2 file if it has been transferred).

Thank you!