Amaranth flour is very similar in texture to Coarse Cornmeal which is often used to make Polenta. Amaranth is naturally gluten-free and has a high starch content making it ideal to add some stickiness to other gluten-free flours.
Coconut flour is suitable for bread, cake, biscuit baking with a high fibre count and a natural self raising tendency. It does have a delicious coconut aroma but the flavour diffuses somewhat in the baking process.
Tapioca is a very fine, white, starchy flour which is used commonly in gluten free baking to help bind and raise cakes and breads. It has no flavour, so it can also be used similarly to potato flour or corn flour to thicken up soups, stews and sauces.