It's only been available for a couple of weeks and HeyWire is already one of the most popular apps for the iPhone and iPod touch. Why? Because it lets you text friends and family for free using a real number. And, unlike competing apps like Textfree Unlimited, you're not just limited to the U.S., Canada, and Mexico. The app lets you SMS contacts in 114 countries. HeyWire is social, too. You can send out text messages and messages to Facebook friends at the same time, and your inbox shows you with a little icon which services your messages are coming from so it's easy to keep track.
Our favorite feature is the ability to ping 10 of your contacts at once, which are simple to select with a tap. HeyWire gets even better on your PC or iPad through the Web-based app (now in beta). You'll see multiple columns with this interface and the added support of Twitter, as well as the major instant messaging clients like AIM, Yahoo! Messenger, Google Talk, and Windows Live Messenger. Another cool feature: when you highlight a given thread in a conversation the bubble gets bigger so the text is easier to read.
This multi-platform messaging service has a lot of intelligence, and it can save you time and money. Expect HeyWire to migrate to other platforms soon, including Android, BlackBerry, and even Google TV.