Many of the apps on this list allow you to offer a variety of pet services in addition to dog walking. This includes dog sitting, boarding, drop-ins, and even doggy daycare. These things are often more lucrative than dog walking, so they may be something to consider if you have the spare time and the means. Many apps on this list also provide the opportunity to care for pets other than dogs, from cats to "horses, pot-bellied pigs, hamsters, snakes, lizards, and even pet shrimp."