One of the coolest aspects of social media marketing is the ability to test, measure and gain real insight into your efforts. There are a ton of free tools and apps available that can help with this. This week’s Cool App is a free Twitter analytics tool that lets you see which of your followers are online now so you know who’s likely to see your tweets.

SocialBro is a plugin that works with Google Chrome and Adobe Air. It gives you a nice overview of your Twitter community – enabling you to see who’s influential and who’s not, and sort them into lists accordingly.

The latest update to the app adds a real-time feature that enables you to see which of your followers are active (which clues you in to who will likely see your tweets), the number of active users each second, the apps they’re using to tweet from, and the languages they’re tweeting in. These are all interesting insights, but the most useful is the window into which of your followers are active, which enables you to segment, tailor and target the content of your tweets.

In addition, you can also focus on a particular Twitter list or search term – like “Silicon Valley real estate,” for example, and learn a bit about the people who are tweeting about that topic. This too can help you segment, tailor and target the content of your tweets for more effective social marketing.

SocialBro considers a user “active” if they’ve tweeted in the last 5 minutes.

Other notable features and uses of the tool include:

• Easy follow-back tools that enable you to efficiently and strategically follow people back
• Discover who has unfollowed you
• Discover the best time to tweet
• Discover who isn’t following you back
• Discover influential people who follow you
• Organize followers into lists
• See your followers on a map

Check out SocialBro for the intelligence you need to effectively use Twitter for your real estate business. You can download the app from the website for free.