Dog Trainer Pro has been around for over 3 years, and the content hasn't changed much because it doesn't need to...it simply works. One thing we liked about Dog Trainer Pro is it's new approach to teaching your dog. They use only non-violent (no choke-collars, no yelling, no punishing, etc.) techniques, which supposedly allows your dog to learn faster. Dog Trainer Pro offers a lot of material on dog obedience as well as fun dog tricks and it also gives you information about common dog breeds such as grooming and exercise needs. Don't let the price fool you, this guide is great for any dog owner.