Rent-vs-Value Search Map Overlay?

[Jefferson Kim]

Zillow has a nice feature, Rent Zestimate that gives me a very quick glance at what kind of rent / value ratio a property may potentially have.

Does anyone know of a website that will allow me to see an overlay of the percentages or search by that parameter?

So for example, if I only want to see properties within a 1.5% - 2% ratio or only seeing properties with a ratio above 1.2%

I guess I could custom program something for my own use using Zillow's API, but I was hoping there may be something already preexisting.