Tomato Powder is simply dehydrated tomato. It can be reconstituted into paste by just adding a small amount of water. It is a great thickener for sauces, and is a wonderful substitute for tomato paste. It also works well in marinades, salad dressings, dry rubs and can be mixed with ground beef to include the tomato flavour without the liquid.
Try sprinkling a little on popcorn mixed with a bit of salt.