Dipsea review
Dipsea makes audio fiction with professional writers and narrators. Its listening guide separates a series queue from the offline copies you save in the mobile app, which matters if you plan to keep a story going away from Wi-Fi.
Queue the series in order
The iOS and Android guide says to open a series and tap Play All. That adds its stories to the queue. The offline guide describes a separate step for each story you want to save. Favorite it first, open it in My Library, then download over Wi-Fi. The guide excludes sleep scenes from downloads.

Keeping stories offline and managing the plan
Dipsea’s offline instructions keep saved stories inside the mobile app. Nimja Hypnosis lets patrons keep the MP3s they download while they have access. To cancel Dipsea, use Manage Subscription in your web account if you bought on the website, or the Apple or Google subscription settings if you bought in the app.
Anabel’s take
I'd set up the first few installments at home if I wanted a series for a trip. Play All answers what comes next, and My Library is where I'd make sure each story I wanted was saved.