From Reuters: 'New apps for U.S. renters may keep lax landlords in line'
Check this out:
http://www.reuters.com/article/2014/10/15/us-usa-tenants-tech-idUSKCN0I415W20141015
Could be good, could be bad... I could see this type of thing being abused. RentRocket could be useful for evaluating deals though, if it turns out to be accurate.