Found 1959 D Penny It's nice but on the reverse it has what looks like grease or glue stuck on it its like blended in. What do u think it is ?
Really can't tell, those are terrible photos - they aren't in focus. However, it's not uncommon for a cent to have been glued to a mailer for a variety of reasons... postage was 4c in 1959, so "Here are 4 cents to cover the cost of mailing us your contribution".
Sorry but those aren't any better. Rest the cell phone on something solid like a pile of books. Touch the button lightly, don't stab at it.
Are you able to look at the photos before posting? The obverse looks good, if it wasn't "reconditioned". The gunk on the back could be conserved I think.