Nella M.L.I. è stato nuovamente sollevato questo problema, ne riporto una risposta:
" You can use a .Lock file.
if this file exist for example in ~/.cache/myapp dir then say to the user
that the app is already running ... destroy this file when quitting the app
if the app crash before so the file still exist.. just say to the user if
he is sure to not have launched another time...
Fabien Bodard "