Curved needles, bent needles, or hook needles are incredibly practical when you need to repair or sew items where you can't access the back, for example, on furniture/upholstery or garments with a lot of lining, felt slippers, or other things. Since the needle is curved, you can fix things from the front because you can sew up and down at once!
We also have the Craft Needles from Prym pack, which also contains a leather needle, a sail needle, and some other types.