I just mash strawberries and raspberries and use them instead of jam on a crumpet :)
I saw a recipe on Facebook - 1 cup frozen raspberries and 1/4 cup chia seeds, boil until thick and then pop in the fridge, it has the same consistency as jam, but without any sugar
Asda extra special one has the highest fruit to sugar ratio I've found there. Sometimes my LO get the tiniest smidge on her bread (maybe a quarter of a teaspoon)
St Dalfour is a good one, just fruit no added bits
The ellas kitchen pouches could be used as a jam like the apple and strawberry one. Or just any reduced/no added sugar jam in moderation is fine.