The WolfNet IDX for WordPress plugin provides IDX search solution integration with any WordPress website.
I depend on my real estate website for a lot of my business. Wolfnet has been down for two days straight (resulting in blank pages). I've emailed support 48 hrs ago but no response so far.
It also seems to have issues loading some of the images. If it weren't for the discount broker price, I would choose another service. I guess you get what you pay for.