Zillow
Special feature: Zillow's "Zestimate" feature provides home values for more than 100 million homes nationwide as well as "Rent Zestimates," which are estimated monthly rental prices, on most homes and apartments.
Trulia
Special feature: Trulia can send real-time updates about listings, including price reductions, new properties in the area, open house schedules, and when houses sell.
Redfin
Special feature: Because Redfin is powered by the local MLS (multiple listing service), it helps house hunters save time by showing which homes are already under contract.
Realtor.com
Special feature: Listing agents can add 3D home tours to their listings for users to view.
Dwellr
Special feature: The app uses house hunters' preferences to create a list of the top 25 places and provides information for each one.