Problems in Real Estate listings:

Accuracy (many expired listings out there)- a good MVP would be a third party solution to feed inaccurate listing reports back to Rightmove / Zoopla etc, along with information on what part of the listing was inaccurate.

Shared Flat - finding the perfect room mate. Kinda like a dating app, only for room shares.

As someone else mentioned, Neighbourhoods aggregation of data from Gov websites on Crime, that sort of thing made into a good pluggable in solution using a postcode. .e.g. Pass a Postcode into your MVP API, spit back aggregated neighbourhood info.