Hands down, iHeartRadio is the best completely free streaming-radio app we've seen. Think of it as a Pandora-TuneIn-Radio lovechild, without ads.
Editors' note, July 8, 2015: See CNET's guide to Internet radio services for a more up-to-date evaluation of this service, along with an analysis of how it compares to competitors.
Think of iHeartRadio as a sort of Pandora-TuneIn-Radio hybrid. It lets you stream live radio from more than 1,500 stations around the country and create custom stations based on a song or artist. And did I mention that the custom stations are all ad-free? Just sign in with an e-mail address or Facebook account to get started.
Similar to TuneIn Radio, iHeartRadio offers live streaming of AM/FM radio stations from all over the U.S. If you're searching for your favorite local station, chances are good that you'll find it. The app includes everything from pop, country, rock, electronic, and hip-hop, to talk and college stations. From the Live Stations tab, you can browse by city or genre, or look at a list of only stations that are located near you. The Talk Radio section also presents options including News and Talk, Public Radio, and Sports stations. While you're listening to a live station, you can hit the scan button to have the app jump to a similar offering, even from other parts of the country. Think of this as a more targeted version of the Scan button on your car stereo.
And then, of course, there is the Pandora-like functionality that iHeartRadio offers. To use it, simply hit the Create tab at the top of the main dashboard, and use the Search bar to find a song or artist, just as you would on Pandora. From there, iHeartRadio will create a completely ad-free station based on your selection. Its library consists of more than 15 million songs and 400,000 artists, which means iHeartRadio is fully capable of putting together an enjoyable playlist with both popular hits and more-obscure tracks. And conveniently, all of your stations get saved under the My Stations tab on the main dashboard.
With iHeartRadio, you won't be able to choose your song directly (the way you can with a subscription to Slacker or Spotify), but you can certainly help the service get to know your musical preferences. First, with the familiar Thumbs-up and Thumbs-down buttons, you can let iHeartRadio know which songs you do and don't like. This means that the more songs you rate, the better it gets at playing only what you want to hear. Also, there's the Discovery Tuner, which you can use to adjust the amount of lesser-known music that gets pushed into your custom station. You can set this tuner to Familiar, Mixed, or Less Familiar, the last of which fills your playlist with a variety of songs that aren't so mainstream.
While you're listening to a song, you can hit the "+" button to pull up options to see lyrics, the artist's bio, or create a new custom station based on that particular song. There are also links to buy some songs directly from Amazon MP3. If you don't like the song you're listening to, you get six skips per station. After you use them all up, you'll have to listen to songs in their entirety or switch over to a new station (which will replenish you with six more skips).
One bonus feature I love is iHeartRadio's Sleep Timer. From the settings menu, you can set the app to stop after anywhere from 15 minutes to 3 hours of playback.
While iHeartRadio is certainly impressive, it isn't perfect. I would love to see the app add some of the DVR-like features that TuneIn Radio Pro offers. I realize that adding these features might come at a price, but still, it would be nice to be able to pause, rewind, and record radio content for later playback.
Overall, iHeartRadio is the best completely free streaming radio app I've seen. It takes some of (but not all) the best features from TuneIn Radio Pro and combines them with Pandora-like functionality. The custom stations are ad-free, programming is top-notch, and the app is easy to use.