American "Jello" is a gelatin made from marrow of beef bones, it doesn't have any preserved fruit ingredient (pectin).

In the US "jam" is the whole fruit preserve and "jelly" is the juice-only preserve.

Pectin used in jelly/jam making is sourced from apples. There are a number of fruits that you can cook and will thicken to "jam stage" without additional pectin, things like cranberries (whole fruit) to make cranberry sauce.

I use a vintage Mehu-Liisa steam juicer from Finland to juice lots of fruits, and make jelly from wild (Mustang) grapes (it has a sweet/tart strong flavor), and strawberry jelly after steam juicing and then use the remaining strawberry solids to make a really robust jam.

A friend of mine makes the most amazing pineapple marmalade (though technically there is no skin to involve in the process.) And the pineapple has plenty of pectin so once it reached the right temperature and consistency, take it off the heat. I think he may add a small amount of orange peel to it for flavor.