QPKG Headphones for QNAP 4.1.0 and above.
http://wiki.qnap.com/wiki/QPKG_Development_Guidelines
Tested with TS-251 x86, but it should work with ARM as well.
Compiled https://dl.dropboxusercontent.com/u/6460642/QPKG/Headphones_20160208.qpkg
This QPKG will store your data outside your main headphones directory install:
/share/CACHEDEV1_DATA/.qpkg/Headphones - install path
/share/CACHEDEV1_DATA/.qpkg/Headphones-data - data path