If you're a detective looking for clues, one essential tool of the trade is a magnifying glass. It helps you spot things you might otherwise miss.
If you aren't a detective, a magnifying glass is still something great to have around. You never know when you'll need to read tiny print on a document, minuscule instructions in a cook book, microscopic writing on a computer part or some equally inconvenient text.
Unfortunately, you might not have a magnifying glass just lying around. However, you probably do have a smartphone within arm's reach.
Turning it into a magnifying glass just takes the right app. I recommend the Magnifying Glass with Light for Apple gadgets and Magnificent Magnifier HD for Android users.