PetTech PetSaver You have to shell out a few bucks for it, but this is by far the best pet first aid app on the market today. Have this on your phone to do a quick check on your pet's symptoms and use it to find the nearest emergency pet care facility if you need one.
Pet Master Free This app is especially handy if you have multiple pets! Keep track of your furry friend's vaccinations, ID chip info, insurance, medications, and so much more! (Ad-free version also available for purchase)
Dog Whistle Lite Use this app to replicate the high-pitched whistle professional trainers use to keep pups in line! Includes a frequency adjustor and lots of tips on dog training.