I'm not sure about an app per-se. However, I subscribe to a pretty neat animal site that WILL have the information you're looking for. If not already there, you may want to check out GoPetFriendly.com. Additionally, there is a pretty informative book outhat I have called "DogFriendly.com's US and Canada Dog Travel Guide. This gives one thousands of dog-friendly accommodations, parks, beaches and dog parks, and so much more!~. Either of these two may be a help. I hope so!~
Beth