From my having worked ~8 years in residential real estate (and overseeing dev. and maintenance of an in-house api)...I've learned that real estate data on all those real estate sites (from zillow, to any other broker site, etc.) is very much not clean, not always correct, nor updated at a realistic interval. From a data perspective, it is extremely messy to work with. Plus real estate brokers (and related data brokers) have little incentive to clean up the data, let alone make updates more real-time. This might not be a big issue for personal apps...but just be aware of the not-so-little gaps around real estate data. Now, if someone did this as an exercise to learn about apis, scraping, web browser automation, then by all means enjoy; plenty to learn for sure! But don't expect the data to be as usuable. (Oh, and my claims of data messiness are not limited to automata, as anyone searching for homes can tell you about their disappointments when asking about a home only to hear from the agent: "Sorry, that home was sold, we/someone forgot to take the listing down...").