When you get notifications and are unable to get to them immediately, iOS automatically stacks them on the Lock screen for you so you can see a general overview of what you've missed. The only problem is when you unlock your device, and then lock it again, the notifications disappear from your Lock screen, even if you haven't had the chance to view all of your notifications just yet.
With ForeverNotification, a new free jailbreak tweak in Cydia's BigBoss repository, you can prevent those notifications from disappearing from the Lock screen automatically just because your device gets unlocked.