The latest versions of iOS for iPhone include an excellent Magnifier feature which can turn the iPhone camera and screen into a magnifying glass. (Note the iPhone Magnifier is completely different from the photography related features of iPhone camera, as it’s not intended to take pictures with. When you tap the camera button it does not actually save the picture, it just freezes the magnified item on the screen so that you can focus on it, read it, zoom, pan, or adjust was needed.)
You’re using mail on your iPhone writing a new message, but find you need to refer to something in your inbox or one of your folders. You scowl and close the message, save as a draft, lookup when you need, open the draft again, and finish writing. Apparently you don’t have to do that anymore in iOS 8. Minimize the new message, look up your stuff, and continue. Just hold and swipe the new message down and then back up. (If you did need to go to a draft, you can also press and hold on the drafts icon on the bottom right).