Here is an example of a grave that was a "green pin" in a cemetery. This is a photo that transcribers marked as unreadable.  Is it? Not to a researcher!

This one is hard to read, but there are clues. The name T.M. Skinner is across the top. You can also clearly see the date Feb 12, 186?. My first stop is to go to another website to see if I can figure out who this might be. Find A Grave has the record, within the cemetery, but the photo is hard to read.  However you can see the stones match. Now we know for certain that Lucinda Skinner is buried in the Pisgah Cemetery in Ohio. If you were to use the app, you would be able to walk directly to her grave.  I can type in all of the information that I see on the stone. 

If I want to go further, as a researcher, I can look up the name T.M. Skinner in FamilySearch to see if I can find his information in there. I will place the name of Thomas in as a wild search, as Thomas is a common name. 

This record comes up:

This record matches the maiden name found in the Find A Grave record and can be placed in the notes section of transcription. So, Lucinda Miller Skinner was the Wife of Thomas M. Skinner. We even have their marriage date and the location. Make sure though that it matches up, as people didn't move around very far, typically before 1900. There are exceptions of course. California Gold Rush, Mormon Trail, Texas expansion. (US) Expansionism and colonization from one country to another, Great Britain to India, Australia and Canada etc. Also be sure to place any information in the notes section during transcription.