Yes, apple pips do have a tiny amount of cyanide in them (but why)
This is a from a reasonable source and relates to cherries: https://www.bbc.co.uk/news/uk-england-lancashire-40738573
I think we can assume that apples and cherries are OK to eat. Apple pips are fine and why on earth would you want to crunch through a cherry stone.
Black cherries (prunus serotina) I ate a whole bunch of during late summer. Much smaller than the Prunus avium (sweet cherry) which ripens around early June here. Allegedly the fruit does contain the cyanide producing compounds but without the enzymes. The catch is if you chew the pits (or eat the leaves/stems) it is poisonous. Poisons a lot of horses and other livestock: https://horsedvm.com/poisonous/black-cherry-trees
As linked in the original article - says 150 seeds to a few thousand depending on the apple variety.