How do I turn on app notifications when on the data network?

[Josh28]

I currently have an LG Optimus. When I'm on wifi, I'm notified about incoming messages in facebook, snapchat pictures, etc. But when I'm not near wifi and I have to be on the 4G network, these notifications don't come in. I either have to go into each app individually to check to see if there's anything new, or, and this happens more often, not check until I get home, only to find about 20 different notifications waiting to pop up. I end up not seeing some pretty important messages until it's too late because of this, so I'm wondering if there's any way to get the notifications to pop up when I'm on 4G, because so far I haven't been able to find any way to set that up. Any help is much appreciated!