Several years ago, I found an IPhone at a gas station's entrance/exit. Since it was lying on the exit side, I made the assumption that someone had set it atop their car, forgot about it and drove off.
I pressed some buttons and it called a number. A woman answered in another language. I spoke English and then French to her. She quickly switched to English and replied that it was her son's phone. She enquired as to who I was using her son's phone. I explained about finding the phone and who I was. She asked for my name and address. since I was quite a distance from her home, she asked that I send it to her. She gave me her address and I sent it. I never heard from them again - or so I thought.
Perhaps 6 months later, I received a letter for $20 and a note from the woman explaining that she had completely forgotten to send me a small reward and money to cover the postage.