This is my all-purpose gluten-free flour, but actually it is NOT an all-purpose flour. It is a flour with a particular taste and texture, moist and dense, with lots of fiber and protein. It suits very well recipes with other flavorful ingredients such as molasses, spices, chocolate, carrots, zucchini, bananas.
Also, this recipe goes by weight and is also measured with a scale when used in recipes. I strongly recommend that you buy an electronic scale with a precision of 1 gram if your ever intend to become serious in GF baking.
Substitution of wheat flour for gluten-free flour in any recipe is by weight. You use the exact same weight of GF as you would for wheat. Since the volume per weight of every flour is different, it is not possible to substitute easily based on volume.
All-purpose wheat flour weighs 4 ounces for every imperial cup. Additional precisions on weight/volume conversions can ben easily found on Google by typing "Weight/volume conversion flour".