Long-time lurker, first real post. I'm a casual investor with rentals in NJ and PA, and screening Zillow listings one-by-one was eating my evenings. So I built a Chrome extension for myself that:

- Pulls all data Zillow already shows on the map (price, taxes, est. rent, beds/baths)
- Runs cash flow + cash-on-cash on every visible listing automatically
- Sorts the map results so the top deals float to the top as you pan
- No clicking into each listing to do the math

Just got a triplex in NJ under contract that I found this way — would not have spotted it scrolling normally because it didn't look great on the thumbnail.

Before I share it more widely, I'd love feedback from people who actually do this for a living:

1. What assumptions do you use for vacancy, capex, and management when screening (not underwriting)?
2. Are there data points on Zillow you've found unreliable enough that they shouldn't be trusted in a first-pass filter?
3. Anything obvious I'm missing that would make a screening tool actually useful vs. just another calculator?

Happy to share more about how it works if there's interest. Mostly here to learn from people further down this road than me.