When you select music from your library, it plays back using the built-in media player library. That means the music keeps going when you quit the application, do something else, and then return to the TuneWiki app. I really appreciated that because I often feel trapped by non-Apple media applications. I really wish Pandora could keep playing in the background, for example.
Switching over to streaming radio, it offered a huge selection with many genres. As with my iPod library, it provided ready lyrics but unfortunately for the several Country stations I listened to, coverage for lyrics was spotty. When it found them, great. Otherwise the application displayed a "::Sorry No Lyrics Yet!::" smack in the middle of the album cover. Pop and Rock coverage proved much more extensive. And no, I didn't even test with Broadway musicals this time 'round.
Another problem was that the program does not remember my last station. I'd really like the application to maintain the same kind of persistent user experience for streaming radio that it does for iPod music. But when you return, you have to re-pick a genre and then a station. The "Favorite Stations" section involved just as much work as navigating through genre/station and included duplicates of stations most recently listened to. The developers really should provide settable radio buttons on that tab for quick and direct access to favorite stations.
The video section was my least apprecated. It allows you to search through and play back music from YouTube. And it worked, well, it worked like a YouTube app, offering pretty much nothing special that I could experience, plus it makes you flop the iPhone on its side. No lyrics, no enhancements. I wasn't entirely sure why they added this section to the application but it's there.
Searching videos is fussy. Searching for "Rascal" returned no hits but "Rascal Flatts" produced a bunch. So make sure you spell your search name correctly and fully.
In the end, TuneWiki offers one really great feature and one very good one. First, it syncs lyrics to live iPod and streaming radio and provides live lyric updates as you listen. This is awesome and I enjoyed it a lot. Second, it offers a very nice Internet radio client that was very stable throughout my testing. There are many radio clients on App Store these days and TuneWiki is completely servicable in that arena. Between these two and its free price, it's an application you'll probably want to check out.
One final note, due to Apple's insane new rating policy, the application is rated 12+ because it offers access to YouTube and to uncensored radio stations. Feel free to ignore this, oversee what your children actually do with their devices and talk to your children about appropriate listening choices.