Use APKPure App
Get SfArk-SoundFont-Extractor old version APK for Android
Extract SfArk compressed SoundFont SF2 files.
A simple sfArk to sf2 extractor. This is probably the only dedicated android SfArk extractor. Ported from GPL source provided at http://melodymachine.com.
Quick guide:
Open .sfark file from files button. Choose output directory. Press convert. Conversion log will be dumped at text below the convert button.
Its better to compress the soundfont files with 7z like compressors than sfark. 7z, xz, rar etc are enough to save disk space.
Stay away from sfark & sfpack formats!. Get sf2 files and 7z them. Delete these outdated sfark sfpack formats. SF3 files are now better as they contain audio in form of ogg however support is very low this time.
Developers:
Source of native binaries will be provided upon request if you need. I don't understand why people still use these outdated boring formats.