With Evermusic you can listen to your music directly from SanDisk iXpand Flash Drive and free up space on your iPhone or iPad for photos and other apps. You can save up to 256 GB of space on your iPhone. iXpand is small Flash Drive with lightning connector on the one side and standard usb connector on the other side. You can copy files to this drive from your home computer or iPhone vice versa. Just connect iXpand Flash Drive and open Evermusic app. Navigate to ‘Connect’ tab and you will see attached flash drive on the top of the screen in 'External device' section.
Open iXpand Flash Drive (just tap on the SanDisk icon) and you will see all available folders and total size of content on the top of the screen. In some cases other apps may use your drive and set busy state. In this case you will see warning message. Nothing serious - just close all other apps that uses your flash drive or unplug it and plug again.
Once you opened any folder with music you will see all available audio files. Just tap any file to start playback. You can enable equalizer on the player screen or stream audio content to AirPlay (Sonos, Apple TV) or Google Chromecast device.
All basic operations with your files like MOVE, DELETE, RENAME, CREATE NEW FOLDER also available in built in file manager.
But Evermusic is not only file manager and audio player for your iXpand Flash Drive. This app also builds Music Library where all tracks are grouped by Artist/Album/Genre. You can also create Playlists and change tracks order in audio player queue.
And of course you can copy audio files from flash drive to you iPhone memory.
You can read more about Evermusic here
About iXpand by SanDisk here.