Do you ever need a magnifying glass or a bit of light to read a menu or medicine bottle? If so, check out Magnifying Glass With Light or Glasses. Both are free iOS apps for your iPhone. Both of these apps are easy to use, and you would be wise have one on your iPhone.
Glasses has an elegant design and no ads. Magnifying Glass With Light has banner ads across the bottom. If they bug you or if you want to get some advanced features then you could upgrade to Magnifying Glass With Light Pro, which is currently $1.99. Read about the additional features available in the Pro version.