Zillow Inc. has launched a mobile-enabled collaborative home search and shopping tool, Agentfolio, that's aimed at buy-side agents and their clients, allowing them to search, comment on, review and share homes they are interested in. The tool -- which is free for agents who advertise with Zillow in one of its "Premier Agent" packages, and $25 per month for agents who do not -- is available today in Chicago and coming soon to Boston, New York City and other markets, Zillow said. Video from Zillow promoting Agentfolio. The tool allows an agent to create a folio with clients and team members by entering their email addresses into the system. An agent can create custom searches for each folio and get instant alerts from Zillow when a new property enters the system that might be of...