Services on homescreen jailbroken iphone
This is a fairly common issue on jailbroken devices. It's a harmless bug where usually-hidden system apps suddenly show up, usually after installing a new app. I've seen reports of it happening on devices on iOS 6 with various combinations of tweaks installed, so I'm not sure whether any specific tweak is causing it, or whether it's related to the jailbreak itself. If you use Springtomize to hide Apple apps, you could try un-hiding those apps and seeing if the white icons come back (the hypothesis here is that maybe Springtomize's hidden apps feature is causing the problem for you).