All apps wiped from jailbroken iPhone (iOS 7.0.4) after reboot from battery loss
It's a bug. Your apps aren't gone but just not visible on your Home Screen.

To restore them, reinstall a package through Cydia (either an existing one, or a new one will suffice). Then either respring (can be achieved via WinterBoard) or reboot your device (unnecessary if you reinstall a package that requires SpringBoard to restart, like ClassicDock for example).

I have unfortunately not been able to pin down the exact cause of this.