In a medium saucepan on medium high heat, add in the blueberries. Cook, stirring the blueberries, until the they start to release some juices. Mix in the maple syrup and lemon zest. Cook until the blueberries begin to bubble and boil.
Turn the heat down to medium, and cook, stirring frequently, for 10 minutes. Use a wooden spoon to smush the blueberries open, or use a potato masher (quicker and easier).
Turn the heat down to a simmer and stir in the chia seeds. Cook, stirring frequently, for about 5 minutes. At this point, the jam will look like it's starting to thicken. If not, cook for another 5 minutes. The jam will still be a little runny as it only finishes thickening after it cools.
Allow to cool slightly then transfer to a jar. To quickly cool the jam, set the jar in a bowl of cold water. Cover and store the jam in the refrigerator.
This is not a shelf stable jam. Use within 1 week and keep refrigerated.