Mozes si to podpisat sam 
http://symbianism.blogspot.com/2009/05/switch-off- updated-for-symbian-s60-3rd.html
Ten mod pises ze nechces, ale tie dalsie sposoby su mozne.Switch Off is unsigned. You can sign it yourself with a developer certificate, try to get it signed on Symbian Signed Online, or use the SIS Installer Mod so you can install any unsigned program you like.