Have you noticed that sometimes your iMessages are not in the order you received them? It only happens when you're having a message conversation with someone that goes back and forth quickly; when the sequence is most important.
iOS 11 Update
In iOS 11, Apple added an App Drawer to allow you to quickly access your message apps. The App Drawer is the row of icons that appear below your text box when composing a message.
If you don't use message apps often, you may want to hide the App Drawer.
Here's how to hide the App Drawer in Messages:
1 - Open a Message and Select the App Store icon next to the text box.
Have you ever been part of a group message that is annoyingly active? You want to see the conversation, but don't want the constant interruptions that can be a part of an active group.
In iOS 11, Apple made it much easier to hide the alerts for all messages, but more importantly group messages.
To hide alerts for messages:
1 - Open the messages App and find the conversation
2 - Swipe right to find the 'Hide Alerts' option, and select it.