Walkie-talkies don't offer stellar range unless you spend hundreds for them. This free app gives you a similar experience over the phone. HeyTell doesn't give you a large amount of time to leave your message, but it works just as quickly as a text. It's a good way to sneak someone a voice mail when you can't find working voice coverage.
HeyTell only gives you about 2 minutes to speak your message. This should be enough to say what you need to say, but you might fill up a person's inbox if you try to send longer speech over multiple messages. Sending and receiving is relatively instant, and the messages are compressed enough that they don't swallow much of your data. Audio quality is about equal to your phone's call quality, too. The signup process requires you to give the app plenty of information, but you can get out of it by signing in through Facebook or Twitter. You can also share voice messages on those social networks instead of sending them to multiple people. When you tap the HeyTell's settings menu, it contains a few features -- like a robotic voice changer -- that you have to pay to use. The app's interface leaves plenty to be desired.
If you need to communicate a message that a text can't convey, this app is a good way to send it. Though it's a fun way to communicate, it doesn't really replace calling or texting. However, some will find waiting for their friend's voice response fun enough to use HeyTell as a replacement for other free voice chat apps.