I've tried to cultivate hundreds of pips and fruit stones with fairly limited success.
I've found cutting a tiny hole in Apple pips increases chance of them growing. Unfortunately the bloody goats got into my seedlings and destroyed them all so I'm back to collecting pips again.
I do see wild fruit trees by roads and railways, but considering the millions of pips, stones and seeds that must have been tossed from Windows over the years not many grow into trees and even fewer end up with tasty fruit. Still good for diversity, wildlife, interest, cider though!