Finder (noun)

1. A person or thing that finds something.
2. A device for finding something, such as a metal detector.
3. A part of a camera that helps to locate the subject in the viewfinder.

Origin:

From middle english finder, from old english findere, from findan ("to fin.d")

Examples:

1. The detective was a skilled finder of clues.
2. The metal detector was a useful finder for lost coins.
3. He adjusted the finder on his camera to get a better view of the subject.
4. The GPS device is a great finder for finding the location.
5. The search engine is a finder for finding the information.