What features in iOS 7 make a difference?

Solution 1:

Within Messages.app, you can (finally!) check on the exact time every message was sent and received by swiping message bubbles to the left.

source: http://www.theverge.com/2013/9/18/4741412/the-best-hidden-features-in-ios-7

Solution 2:

Open the compass app, and swipe once to the right. It becomes a level that changes color to help when oriented vertically or horizontally.

Solution 3:

Burst mode photography feature is available on older devices by holding down the shutter button. It does not have the automatic choosing of the best as per the iPhone 5S and I don't think it is as fast.

Tested on iPhone 4, 5 and iPad 3.