TuneIn Radio ($1.99) by Synsion Radio Technologies is a universal radio app for your iPhone, iPod Touch, and iPad.
There are plenty of radio apps out there, but TuneIn Radio is a recent addition and worthy of checking out for any radio listener.
First thing's first, if you have a radiotime.com account, you can log in with it in the app. Doing so will pull in your presets and merge bookmarks. If you don't have an account, the app informs you that you can create a free account at radiotime.com. Bonus: In the iPhone version, there's a fully functional in-app web browser that you can use.
Now that I got that out of the way, let's go into the meat of the app. You'll want to search for your favorite radio stations out of the 40,000+ available, and the iPhone version has a simple Browse screen that lists various methods of browsing.
You can choose from Local Radio, Recents, Talk, Sports, Music, Location, and Language. Selecting any of these will bring you another subcategory list or a listing of stations you can tune into. If you want to get specific, you can even search by station, show, song, or artist.
On the iPad, it's a little different. There's a left sided pane that already splits up searching by Location, Music [genre], Talk, and Sports. It's a little less selection than the iPhone version but provides the same stations.
What if what you want isn't there? If you have a URL for it, just plug it in and it should start playing. This app has you covered!
Once you find a station, select it and it will start playing. Most of the time you'll find an album cover and song info for whatever is playing, but sometimes you won't (like when commercials are playing). TuneIn Radio also lets users listen to podcasts of any radio show if it's available.
Both the iPhone and iPad versions will allow you to bookmark stations, view Last.fm artist stations, Buy from iTunes, choose the quality of the stream (this largely depends on your data connection), set alarm/record/sleep timers, view schedules (if available), and report any problems with the stream.
The iPhone version also has an optional clock display that will be a transparent layer on top of the "Now Playing" screen. The iPad version also currently requires a Safari workaround to be able to play in the background since iOS 4.2 is not available yet. I'm sure once it is, the developers will update the app promptly to enable background playing like on the iPhone with iOS 4.1.
TuneIn Radio also has the nice addition of allowing users to record any station they are listening to. This is a very nice feature to help you remember something that you may want to look into later on. The only other app that I know of that has this feature is Snowtape Radio, which only has a limited amount of Internet streaming stations and doesn't cover the wide variety that TuneIn Radio has.
Keep in mind that these recordings take up space on your iDevice, so use it sparingly unless you have tons of room to spare. All recordings are kept in a separate Recordings section that appears in both the iPhone and iPad versions
The best part of TuneIn Radio is that it's like a TiVO for radio. You can pause live streams and even rewind and fast forward to any point within 30 minutes. On stations that display song information, you can even skip directly to the beginning of a song. This is a feature that I'm sure any radio listener can appreciate - you can even skip annoying commercials if you had the stream paused!
Want to try something new? The app can recommend related and recommended streams, shows, and even genres to you. This is great for exploring and finding new stations that could become your next favorites.
TuneIn Radio is an exceptional mobile radio app that is worthy of a place on your home screen. The recording and TiVO-like features make it worth the measly $2 asking price for it. If you're worried about them not carrying your favorite station, you can quickly check here: http://www.tunein-radio.com/stations.html before you decide to buy the app. Don't carry it? You can contact the developers regarding it.
It's feature-packed and looks good, especially on the iPad. Definitely for all radio fans.