If you prefer a more traditional iMessage look, find the app drawer more irritating than useful, or just never use any additional apps, you can get rid of the app drawer.
Here is what you need to do:
- Open the Messages app.
- Go to an iMessage conversation.
- Tap on the greyed App Store icon between the text box and the camera icon to push it away.
- Done :)
It's never too late to bring the "old-school" feel of your iMessage app :)