Backstory: Two nights ago, Julia found a stray cat in our local Target parking lot. She bought it food and lured it into her car. The cat wasn't clipped (ear) and seemed to be fairly healthy. Julia's worry was the cold near 0 degree temperatures. She posted on facebook and a rescuer fostered the cat for the night. The rescuer just happened to glance at her phone before bed and almost missed the post, nobody else responded.
The Idea: An alert service for fosters and pet rescuers.
Deep Dive: This is more of a good will/feels good idea that will help out your local community. You would build a platform for animal fosters and rescuers to be notified when someone finds a stray or lost pet nearby. Whenever someone finds a stray they would be able to upload pictures, location and a short description.
The app would facilitate conversation to bring the lost animal to the foster. It could also have information about local animals that are clipped and understood to be stray/feral cats.
Validation: Living in the city, people are constantly posting on a local facebook group finding lost animals.
Monetization: You would only be able to sell ads on this platform, there is no exchange of money.