I currently have to use my iPod to listen to music in the car for free. I wondered if iPhone works like an offline iPod?
Is there a way use home sharing and play musuic without streaming it (data use) with an iPhone?
Yes - there are three ways to accomplish this to have the Music app on an iPhone or iPad work without cellular connection and streaming data:
All three of these need you to set up playlists and connect to WiFI and download those playlists / albums / songs so that the songs you want to be offline are cached. All of this data will come through WiFI and not cellular.
Now you can turn off everything (airplane mode) relating to wireless and WiFI and restart the phone. Open music and verify that the songs you downloaded will play in full. Now that you know how to cache - you can add playlists / songs / albums and cache them locally so you don't need to stream.
You don’t need another app d\to do this, but you might love the cesium player which makes it super easy to only see and play cached songs from your local library.