iOS still doesn't have quick access to apps like certain Android launchers, but GigaOm notes that you can use the Notification Center to quickly access certain apps. Here's how.
In Notification Center, tapping on notifications launches the app they're associated with. Your first instinct might be to clear out all notifications associated with each app to keep your center clear. Don't. Just leave one for each app, and then you can use the Notification Center as a quick launcher for those programs.
Since the Notification Center tells you which notifications are unread, keeping one notification for each app in the menu doesn't heavily impede your ability to see new messages, and it can save you from swiping through a lot of screens for those heavily used apps. Hit the link to read more.