I recently bought a Galaxy s5. Some apps (such as email) will give me notifications right away in the bar; however, for most (such as bleacherreport and snapchat) I will get the notifications hours later. For instance, last night the Devils played a game and I received 2 snapchats. On my Galaxy s3 I received these updates right away: about 5 minutes after the Devils finished and a few minutes after each snap. I didn't get any by the time I went to sleep at 1:00ish. I woke up and had notifications for both, including for the snaps I had already viewed. (I should probably add that when I do get these notifications very delayed, they all tend to happen at once). I checked and Wifi is always on (even when phone is locked) etc.