I was privy to some info in confidence by the nanny who is my friend .    

OR if that fails, hire a plumber that does sewer cameras or pipe locating, they will have devices that they can track...

The answers to dog barking, leaves falling, parked cars, surveillance cameras, cutting down trees, paint spray on new car, paint peeling, loose boards in fence, dog barking, etc aren’t the answer.  

Same tool, different results.Parallel this to a camera: A camera is a tool.

You may need to camera scope down your existing sewer line to see how deep and if it's feasible to connect to. 3.

I finally purchased a surveillance system,  and captured and recorded the tenant on camera stealing  a package.  

I'm not sure if I'm thinking too much into it, but do you use a newspaper or something in addition to your camera/phone to prove time stamped photos. 

@Enyi Ajoku Have an outdoor security camera system set up on the outside front & back of the property, as well as additional lighting.

Is there an app out there that will let me document repairs and maybe even allow me to use my camera to image search various things that might need repair and estimate costs in my area?

Solution 1: Plumbing company ran the camera and quote 12k to dig up and replace all underground pipes with PVC from the store to the main drain and all pipes outside to the main drain.