To read when a message was sent just simply use one finger over a message to steady the screen and "pull/swipe" to the left.
This is what it looks like. It even tells you when you sent a message.
You can scroll up and down while looking at the times and messages are grouped into different days which can be seen in the middle of the screen between messages.
- 1.0 iPhone 4 or newer
- IOS 7/8