I recently found out a solution to get the accompaniment to my phone, so that I can play along with it. There are some quality-wise compromises but overall it is good enough for me.
Usually the music has several tracks and I was using songsterr to find tabs. The problem is that, it is not providing a way to suppress the track you are playing while keeping the others on. I guess a PRO version may enable this feature though.
The trick is to get the .gp4 or .gp5 file and convert it with some softwares.
For example, I go to gtptabs.com to download the tabs file
After the file is downloaded, open it with TuxGuitar.
You can see the two tracks here:
Then we go File-Export-“Export Midi” to save it to be a midi file.
We open the saved midi file in GarageBand and mute the melody track.
Now you can either go Share-“Export Song to Disk..” and save it as an audio file, or go Share-“Project to GarageBand for iOS…” to save it as a file that you can open and play with the GarageBand installed on your iPhone/iPad.
Now enjoy 🙂
The midi file does not sound very authentic, so I guess this is only good for practice.